Moscow (CNN) Authorities in Belarus have announced the arrest of 33 Russian mercenaries on suspicion of terrorism, accused of trying "to destabilize" the country ahead of August's presidential election, the state-run news agency Belta reported.
The detentions come as tensions grow between the neighboring countries and as a rift emerges between their two strongmen leaders, Russian President Vladimir Putin and Belarusian President Alexander Lukashenko, once staunch allies.
Authorities have opened a criminal investigation against the men on suspicion of terrorism, according to Belarus's Security Council chief, Andrey Ravkov. They face up to 20 years in prison if convicted.
Belarusian law enforcement agencies said Wednesday they had received information about more than 200 militants arriving in Belarus and detained over 33 people identified as fighters from the Wagner private military company, a shadowy enterprise widely believed to be sponsored by St. Petersburg businessman Yevgeny Prigozhin.
Prigozhin is a Russian oligarch often referred to as "Putin's chef" for his close ties to the Kremlin. Wagner fighters have been previously deployed to Ukraine, Syria and Libya, among other places.
Lukashenko is likely to use his powerful propaganda machine to project an image of himself as a defender of the country against foreign threats as elections draw closer.
Belarusian state TV released video of the raid showing several of the men being detained in a hotel room. One man is shown handcuffed face down in bed. The video also showed alleged personal possessions of detainees, including passports, US dollars, other foreign currency and phones.
Prigozhin's Concord group of companies repeated its denial that Prigozhin owned Wagner, in a comment posted on their VKontakte social media page late Wednesday. Prigozhin "has nothing to do with Wagner, does not finance them and does not follow their whereabouts," it said.
Prigozhin was sanctioned by the US for funding the Internet Research Agency, which US intelligence agencies say meddled in the 2016 US presidential election.
Belarus is holding its presidential election on August 9 following weeks of mass protests in support of opposition candidates, and against Lukashenko's sixth reelection campaign. In a Belarusian Security Council meeting Thursday, officials said security measures would be tightened at all electoral events, according to a statement by the committee and state media reports. That would effectively restrict mass events and subject protesters to thorough checks. Border controls with Russia will also be tightened.
Candidates running against Lukashenko were called to the unexpected meeting at the Central Elections Committee headquarters, where Ravkov warned that many more militants were still in the country and that "provocations" were expected. He said they posed "a threat to the safety of citizens during campaign events held by presidential candidates."
Authorities might also shut down or restrict internet access during demonstrations, according to one of the presidential candidates, Andrey Dmitriev, who spoke to local news organization Tyt.by.
"I've asked Ravkov whether it's possible that the internet will be restricted during demos," he said. "I was told that they do not exclude this in case they deem that [the internet] poses a direct threat to the security of the country."
Belta published a list containing the full names of what it said were the detained men. The Belarusian state security committee arrested the suspects with the help of special police units. The Belarusian investigative committee has opened an inquiry.
Lukashenko said he would be demanding an explanation from Russia, according to Belta. The Russian embassy in Belarus said in a tweet it had received an official notification from the authorities regarding the detentions.
The Kremlin said on Thursday it was not aware of any illegal activities by the Russians arrested in Belarus and that it did not yet have all the details about the arrests.
"Of course there are some insinuations that it's some Russian organizations sending someone to destabilize the situation in Belarus. This is nothing but insinuations. Russia and Belarus are allies and closest partners so this is out of question," Kremlin spokesperson Dmitry Peskov said in a conference call.
Russian writer Zakhar Prilepin, who previously fought in eastern Ukraine on the separatists; side, wrote on his Facebook page that he had identified several men who served in his battalion among those arrested in Belarus. He suggested that the men were most likely passing through Belarus to fight elsewhere, and that their detentions were being used by Lukashenko for leverage ahead of the election.
"But if the Belarusian leadership starts using this story for its own purposes, it will certainly look ridiculous. This looks like a well-known story when well-trained people move to certain destinations where they have their own business, they do not need Belarus," Prilepin added. "And I'm sure the Belarusian special services are well aware that three dozen men in camouflage were going somewhere else."
Out of the 33 men detained, 14 have been identified as veterans of the conflict in Eastern Ukraine, according to Ravkov. The Ukrainian ambassador has also been called on to provide explanations, he said.
Ukraine said it will work on the possible extradition of its citizens and added that it was developing "good neighborly relations" with Belarus.
"Ukraine has long warned that members of the Russian occupying forces and illegal armed groups that participated in hostilities in eastern Ukraine are being used elsewhere in the world and pose a threat," the Ukrainian Foreign Ministry said in a statement.
"The identification of these militants in Belarus confirms this and indicates that they can be used to destabilize the situation in Belarus on the eve of the presidential elections."
The US military recently accused Russia of sending Wagner mercenaries, along with weapons like anti-aircraft systems, to operate on the front lines of the conflict in Libya. The US Africa Command has also released satellite photos that they say show Wagner vehicles and Russian military equipment in Libya supporting anti-government rebels in the country's civil war.
Among the detained men's items confiscated by authorities at the hotel was a document written in Arabic, showing a prayer used by a Muslim Sunni religious order called al-Qadiriyya, popular among Muslims in Arab countries in Northern Africa. The document and foreign currency found in their belongings suggest that the fighters may have been traveling to another destination via the Belarusian capital.
"The visitors drew attention to themselves as they behaved uncharacteristically for Russian tourists and wore a uniform, military-style clothing. They didn't drink alcohol, didn't visit any places of entertainment, [and] kept themselves away from everyone to try and not to draw attention to themselves," Belta report said.
Aleksey Kondratyev, a Russian senator and colonel with the military's GRU intelligence unit, said the details of the detentions needed to be "checked and law enforcement of both countries needs to cooperate on this," Russian state-run news agency RIA Novosti reported.