HANOI, Vietnam, May 7 (UPI) —

Vietnamese Navy and Chinese vessels collided in the South China Sea as Vietnam attempted to prevent the Chinese from installing an oil rig in contested waters.




Vietnamese officials claim the Chinese ships intentionally tried to ram their vessels. The incident is the most serious between the two countries at sea, and dozens of boats are presently in the area.




It is the third time in the past several days Chinese ships have collided with Vietnamese ships, maritime police official Ngo Ngoc Thu said in Hanoi Wednesday. Chinese officials said Wednesday the oil rig was within Chinese territorial waters.




"The disruptive activities by the Vietnamese side are in violation of China’s sovereign rights," Hua Chunying said.




Several Vietnamese sailors were injured in the collision, an official said, and although no shots were fired, water cannons were used by the Vietnamese Navy.




China has claimed ownership of significant parts of the South China Sea. Vietnam, the Philippines, Brunei, Malaysia and Taiwan have competing claims.