(CNN) Aerial photos taken by the US Navy show just how close a US Navy ship came to colliding with a Chinese warship that had challenged the US vessel's presence in the South China Sea.
The guided-missile destroyer USS Decatur was performing a "freedom of navigation" operation on Sunday, sailing close to Chinese-claimed reefs in the Spratly Islands, when it was approached by a Chinese destroyer, the Lanzhou.
The US Navy said in a statement Monday that the two ships came within 45 yards (41 meters) of each other, as the Chinese warship "conducted a series of increasingly aggressive maneuvers accompanied by warnings for the Decatur to depart the area."
The two ships could have been seconds away from a collision, said Carl Schuster, a former US Navy captain with 12 years at sea who looked at the photos at the request of CNN.
Taken by a US Navy aircraft but not released by the US Navy, the four photos were verified for CNN by three US officials. They were published on the gcaptain blog site, which describes itself as an "interactive community of maritime professionals."
The images show the Lanzhou approaching the Decatur from behind and to the left of the US ship.
In this situation, under international naval law, the US destroyer would have right of way and be required to maintain direction and speed, Schuster said. The onus would be on the Chinese ship to keep safe distance from and maneuver past the US ship.
But the Chinese ship turned towards the right as it came close to the Decatur, trying to cut across the US ship's bow and forcing the US captain to perform a "radical maneuver," essentially throwing the 500-foot-long, 8,500-ton warship into reverse, he said.
"It's like slamming on the brakes and turning to the right to avoid a crash on the road," said Schuster, now a Hawaii Pacific University professor.
"The Chinese ship certainly violated the rules of the road," Schuster said.
A Chinese Defense Ministry spokesman said Tuesday that its warship was simply defending Chinese sovereignty in the Spratlys, where Beijing has built up fortifications on man-made islands that were once small reefs.
"The Chinese military will resolutely perform its defense duties and continue to take all necessary measures to safeguard our sovereignty and the regional peace and stability," spokesman Wu Qian said.
Sunday's near-collision comes after weeks of friction between Washington and Beijing over a range of issues.
Late last week US Secretary of Defense James Mattis pulled out of a planned visit to Beijing later in October, two US officials told CNN.
Mattis had originally planned to visit the Chinese capital to meet with senior Chinese officials to discuss security issues. The last-minute cancellation of the unannounced trip has not been publicly confirmed by the Pentagon.
Earlier in the week, the Chinese government canceled a port visit to Hong Kong by the USS Wasp, a US Navy amphibious assault ship.
Then last Friday, the US Navy released a series of photos showing troops aboard the 40,000-ton Wasp taking part in a live-fire exercise in the South China Sea, firing on inflatable targets with mounted machine guns and sniper rifles.
Also last week the US flew B-52 bombers over the South China Sea and East China Sea.
But it is the "freedom on navigation" operations like the one the USS Decatur performed on Sunday that seem to spike tensions the most.