Editor's Note: (All of the witnesses to this massacre have been given pseudonyms at their request due to fears of retribution. )
Abraham began burying the bodies in the morning and didn't stop until nightfall.
The corpses, some dressed in white church robes drenched in blood, were scattered in arid fields, scrubby farmlands and a dry riverbed. Others had been shot on their doorsteps with their hands bound with belts. Among the dead were priests, old men, women, entire families and a group of more than 20 Sunday school children, some as young as 14, according to eyewitnesses, parents and their teacher.
Abraham recognized some of the children immediately. They were from his town in Ethiopia's northern Tigray region, Edaga Hamus, and had also fled fighting there two weeks earlier. As clashes raged, Abraham and his family, along with hundreds of other displaced people, escaped to Dengelat, a nearby village in a craggy valley ringed by steep, rust-colored cliffs. They sought shelter at Maryam Dengelat, a historic monastery complex famed for a centuries-old, rock-hewn church.
On November 30, they were joined by scores of religious pilgrims for the Orthodox festival of Tsion Maryam, an annual feast to mark the day Ethiopians believe the Ark of the Covenant was brought to the country from Jerusalem. The holy day was a welcome respite from weeks of violence, but it would not last.
A group of Eritrean soldiers opened fire on Maryam Dengelat church while hundreds of congregants were celebrating mass, eyewitnesses say. People tried to flee on foot, scrambling up cliff paths to neighboring villages. The troops followed, spraying the mountainside with bullets.
A CNN investigation drawing on interviews with 12 eyewitnesses, more than 20 relatives of the survivors and photographic evidence sheds light on what happened next.
The soldiers went door to door, dragging people from their homes. Mothers were forced to tie up their sons. A pregnant woman was shot, her husband killed. Some of the survivors hid under the bodies of the dead.
The mayhem continued for three days, with soldiers slaughtering local residents, displaced people and pilgrims. Finally, on December 2, the soldiers allowed informal burials to take place, but threatened to kill anyone they saw mourning. Abraham volunteered.
Under their watchful eyes, he held back tears as he sorted through the bodies of children and teenagers, collecting identity cards from pockets and making meticulous notes about their clothing or hairstyle. Some were completely unrecognizable, having been shot in the face, Abraham said.
Then he covered their bodies with earth and thorny tree branches, praying that they wouldn't be washed away, or carried off by prowling hyenas and circling vultures. Finally he placed their shoes on top of the burial mounds, so he could return with their parents to identify them.
One was Yohannes Yosef, who was just 15.
"Their hands were tied ... young children ... we saw them everywhere. There was an elderly man who had been killed on the road, an 80-something-year-old man. And the young kids they killed on the street in the open. I've never seen a massacre like this and I don't want to [again]," Abraham said.
"We only survived by the grace of God."
Abraham said he buried more than 50 people that day, but estimates more than 100 died in the assault.
They're among thousands of civilians believed to have been killed since November, when Ethiopian Prime Minister Abiy Ahmed, who was awarded the Nobel Peace Prize in 2019 for resolving a long-running conflict with neighboring Eritrea, launched a major military operation against the political party that governs the Tigray region. He accused the Tigray People's Liberation Front (TPLF), which ruled Ethiopia for nearly three decades before Abiy took office in 2018, of attacking a government military base and trying to steal weapons. The TPLF denies the claim.
The conflict is the culmination of escalating tensions between the two sides, and the most dire of several recent ethno-nationalist clashes in Africa's second-most populous country.
After seizing control of Tigray's main cities in late November, Abiy declared victory and maintained that no civilians were harmed in the offensive. Abiy has also denied that soldiers from Eritrea crossed into Tigray to support Ethiopian forces.
But the fighting has raged on in rural and mountainous areas where the TPLF and its armed supporters are reportedly hiding out, resisting Abiy's drive to consolidate power. The violence has spilled over into local communities, catching civilians in the crossfire and triggering what the United Nations refugee agency has called the worst flight of refugees from the region in two decades.
The UN special adviser on genocide prevention said in early February that the organization had received multiple reports of "extrajudicial killings, sexual violence, looting, mass executions and impeded humanitarian access."
Many of those abuses have been blamed on Eritrean soldiers, whose presence on the ground suggests that Abiy's much-lauded peace deal with Eritrean President Isaias Afwerki set the stage for the two sides to wage war against the TPLF -- their mutual enemy.
The US State Department, in a statement to CNN, called for Eritrean forces to be "withdrawn from Tigray immediately," citing credible reports of their involvement in "deeply troubling conduct." In response to CNN's findings, the spokesperson said "reports of a massacre at Maryam Dengelat are gravely concerning and demand an independent investigation."
Ethiopia responded to CNN's request for comment with a statement that did not directly address the attack in Dengelat. The government said it would "continue bringing all perpetrators to justice following thorough investigations into alleged crimes in the region," but gave no details about those investigations.
More than three weeks after CNN published this investigation, the Eritrean embassy of the UK and Ireland responded on March 22 by denying allegations of wrongdoing by Eritrean soldiers and denying that Eritrean troops were in Ethiopia.
The TPLF said in a statement to CNN that its forces were nowhere near Dengelat at the time of the massacre. It rejected that the victims could have been mistaken for being TPLF and called for a UN investigation to hold all sides accountable for atrocities committed during the conflict.
Still, the situation inside the country remains opaque. Ethiopia's government has severely restricted access to journalists and prevented most aid from reaching areas beyond the government's control, making it challenging to verify accounts from survivors. And an intermittent communications blackout during the fighting has effectively blocked the war from the world's eyes.
Now that curtain is being pulled back, as witnesses fleeing parts of Tigray reach internet access and phone lines are restored. They detail a disastrous conflict that has given rise to ethnic violence, including attacks on churches and mosques.
For months, rumors spread of a grisly assault on an Orthodox church in Dengelat. A list of the dead began circulating on social media in early December, shared among the Tigrayan diaspora. Then photos of the deceased, including young children, started cropping up online.
Through a network of activists and relatives, CNN tracked down eyewitnesses to the attack. In countless phone calls -- many disconnected and dropped -- Abraham and others provided the most detailed account of the deadly massacre to date.
Eyewitnesses said that the festival started much as it had any other year. Footage of the celebrations from 2019 shows priests dressed in white ceremonial robes and crowns, carrying crosses aloft, leading hundreds of people in prayer at Maryam Dengelat church. The faithful sang, danced and ululated in unison.
As prayers concluded in the early hours of November 30, Abraham looked out from the hilltop where the church is perched to see troops arriving by foot, followed by more soldiers in trucks. At first, they were peaceful, he said. They were invited to eat, and rested under the shade of a tree grove.
But, as congregants were celebrating mass around midday, shelling and gunfire erupted, sending people fleeing up mountain paths and into nearby homes.
Desta, who helped with preparations for the festival, said he was at the church when troops arrived at the village entrance, blocking off the road and firing shots. He heard people screaming and fled, running up Ziqallay mountainside. From the rocky plateau he surveyed the chaos playing out below.
We could see people running here and there ... [the soldiers] were killing everyone who was coming from the church," Desta said.
Eight eyewitnesses said they could tell the troops were Eritrean, based on their uniforms and dialect. Some speculated that soldiers were meting out revenge by targeting young men, assuming they were members of the TPLF forces or allied local militias. But Abraham and others maintained there were no militia in Dengelat or the church.
Marta, who was visiting Dengelat for the holiday, says she left the church with her husband Biniam after morning prayers. As the newlyweds walked back to their relative's home, a stream of people began sprinting up the hill, shouting that soldiers were rounding people up in the village.
She recalled the horrifying moment soldiers arrived at their house, shooting into the compound and calling out: "Come out, come out you b*tches." Marta said they went outside holding their identity cards aloft, saying "we're civilians." But the troops opened fire anyway, hitting Biniam, his sister and several others.
"I was holding Bini, he wasn't dead ... I thought he was going to survive, but he died [in my arms].
The couple had just been married in October. Marta found out after the massacre that she was pregnant.
After the soldiers left, Marta, who said she was shot in the hand, helped drag the seven bodies inside, so that the hyenas wouldn't eat them. "We slept near the bodies ... and we couldn't bury them because they [the soldiers] were still there," she said.
Marta and other eyewitnesses described soldiers going house to house through Dengelat, dragging people outside, binding their hands or asking others to do so, and then shooting them.
Rahwa, who was part of the Sunday school group from Edaga Hamus and left Dengelat earlier than others, managing to escape being killed, said mothers were forced to tie up their sons.
"They were ordering their mothers to tie their sons' hands. They were taking them barefoot and killing them in front of their mothers," Rahwa said eyewitnesses told her.
Samuel, another eyewitness, said that he had eaten and drank with the soldiers before they came to his house, which is just behind the church, and killed his relatives. He said he survived by hiding underneath one of their bodies for hours.
"They started pushing the people out of their houses and they were killing all children, women and old men. After they killed them outside their houses, they were looting and taking all the property," Samuel said.
As the violence raged, hundreds of people remained in the church hall. In a lull in the gunfire, priests advised those who could to go home, ushering them outside. Several of the priests were killed as they left the church, Abraham said.
With nowhere to run to, Abraham sheltered inside Maryam Dengelat, lying on the floor as artillery pounded the tin roof. "We lost hope and we decided to stay and die at the church. We didn't try to run," he said.
Two days later, the troops called parishioners down from the church to deal with the dead. Abraham said he and five other men spent the day burying bodies, including those from Marta's household and the Sunday school children. But the troops forbid them from burying bodies at the church, in line with Orthodox tradition, and forced them to make mass graves instead -- a practice that has been described elsewhere in Tigray.
Abraham shared photos and videos of the grave sites, which CNN geolocated to Dengelat with the help of satellite image analysis from several experts. The analysis was unable to conclusively identify individual graves, which witnesses said were shallow, but one expert said there were signs that parts of the landscape had changed.
The initial bloodshed was followed by a period of two tense weeks, Abraham said. Soldiers stayed in the area in several encampments, stealing cars, burning crops and killing livestock before eventually moving on.
Tedros, who was born in Dengelat and traveled there after the soldiers had left, said that the village smelled of death and that vultures were circling over the mountains, a sign that there may be more bodies left uncounted there.
"Some of them were also killed in the far fields while they were trying to escape and most of them were eaten by vultures before they got buried, it was horrible. [The soldiers] tied them and killed them in front of their doors, and they shot them in the head just to save bullets," he said.
Tedros visited the burial grounds described by eyewitnesses and said he saw cracks in the church walls where artillery hit. In interviews with villagers and family members, he compiled a death toll of more than 70 people.
The families hope that the names of their loved ones, which Tedros, Abraham and others risked their lives to record, will eventually be read out at a traditional funeral ceremony at the Maryam Dengelat church -- rare closure in an ongoing conflict.
Three months after the massacre, the graves in Dengelat are a daily reminder of the bloodshed for the survivors who remain in the village. But it has not yet been safe enough to rebury the bodies of those who died, and that reality is weighing on them.
Update, March 22: A comment from the Eritrean embassy of the UK and Ireland has been added to this story.
Correction: An on-screen title in an earlier version of the video in this story misstated the date of CNN-obtained footage from Tigray. It was filmed in 2021.