In this photo released by Vietnam Coast Guard, a Chinese ship, left, shoots water cannon at a Vietnamese vessel, right, while Chinese Coast Guard ship, center, sails alongside in the South China Sea off Vietnam's coast, Wednesday, May 7, 2014. Chinese ships are ramming and spraying water cannons at Vietnamese vessels trying to stop Beijing from setting up an oil rig in the South China Sea, according to Vietnamese officials and video evidence Wednesday, a dangerous escalation of tensions in disputed waters considered a global flashpoint. (AP Photo/Vietnam Coast Guard)

Hanoi, Vietnam -

Vietnam has shown video footage showing a Chinese coast guard vessel steaming into the back of a Vietnamese fishing boat and tipping it over.

The video released to the media on Thursday appears to confirm Vietnam's version of the incident in the South China Sea on May 26.

The incident was the most serious between ships from the two countries since Beijing dispatched an oil rig to a disputed section of the sea on May 1.

China has said that the much smaller Vietnamese fishing vessel rammed into its ship. Vietnam reacted furiously, and sent ships to the region to confront the rig.

China insists it has done nothing wrong and is refusing to withdraw the rig.

The tensions are the most serious in years in the oil- and gas-rich waters. - Sapa-AP