Vietnam on 6 May 2014 accused China to place an oil rig near Paracel islands. The 1 billion US dollar rig is owned by China's state-run CNOOC oil company and it drilling south of Hong Kong.
Vietnam said that Chinese ships repeatedly rammed and used water cannons against Hanoi's patrol vessels in the South China Sea, where Beijing has placed an oil rig in disputed waters near the Paracel islands.
According to the deputy head of Vietnam's national border committee, there were as many as 80 Chinese vessels, including seven military ships, deployed to guard the rig.
The Maritime Safety Administration of China (MSAC) announced that all vessels should stay 1.6 kilometers away from the rig, expanding that to five kilometers on 6 May 2014.
Earlier, China announced it had placed a state-run oil rig near the Paracel Islands, 220 kilometers from Vietnam's shores, in the area Hanoi claimed as its exclusive economic zone.
About Paracel Island
The Paracel Islands is a group of islands in the South China Sea whose sovereignty is disputed by the People's Republic of China and Vietnam.
All of the islands are currently controlled as part of China's Hainan Province, which in July 2012, established Sansha City to administer the three townships under its jurisdiction.
The islands include over 30 islets, sandbanks and reefs over a maritime area of around 15,000 square kilometres with less than 8 square kilometres of land.
Where: near Paracel islands
When: 6 May 2014