A Chinese ship, left, shoots water cannon at a Vietnamese vessel, right, while a Chinese Coast Guard ship, center, sails alongside in the South China Sea off Vietnam's coast on Wednesday. (Vietnam Coast Guard via Associated Press)

Chinese ships have been ramming into and firing water cannons at Vietnamese vessels that are trying to stop Beijing from putting an oil rig in the South China Sea, according to officials and video footage released Wednesday, in a dangerous escalation of tensions over waters considered a global flash point.

Officials said several boats have been damaged and at least six Vietnamese aboard have been injured.

Elsewhere in the sea, Philippines authorities arrested 11 Chinese fishermen for allegedly catching endangered turtles, angering Beijing.

China recently has been harassing Vietnam and Philippine vessels and fishermen in the potentially oil- and gas-rich waters it claims almost in entirety — a claim that many international law experts consider shaky.

But China’s deployment of the oil rig May 1 with escort ships is seen as one of its most provocative steps in a gradual campaign of asserting its sovereignty in the South China Sea. With neither side showing any sign of backing down, the standoff raises the possibility of more-serious clashes.

Hanoi, which has no hope of competing with China militarily, says it wants a peaceful solution.