Clashes at sea as Vietnamese state TV airs footage of Chinese vessels ramming into a Vietnamese fishery boat.
VTV says the fishery control boat was surrounded by 7 Chinese vessels -- one of which rammed into its left flank.
No one was hurt in the collision.
Last Friday, China announced it was moving a second oil rig in the South China sea closer to Vietnam's coast.
This comes as Vietnam is increasingly concerned about China's growing assertiveness in the South China Sea, where sovereignty over countless islands and reefs is in dispute.
China claims about 90 percent of the potentially energy-rich South China Sea. The Philippines, Vietnam, Malaysia, Brunei and Taiwan also have claims to parts of the waters.
