Vietnam and China ships 'collide in South China Sea'
7 May 2014 Last updated at 19:47 BST
Vietnamese naval ships and Chinese vessels have collided in the South China Sea, according to Vietnamese officials.
The Vietnamese navy was trying to prevent the Chinese from setting up an oil rig in an area claimed by both nations.
The incident is the most serious at sea between the countries in years.
Hoang Nguyen reports.