NAYPYIDAW/HANOI - Vietnam's Prime Minister Nguyen Tan Dung has urged his Asean counterparts to protest against what he termed China's "serious violation" in the South China Sea, as thousands of Vietnamese protesters took to the streets yesterday to decry Beijing's deployment of a deep-water drilling rig in contested waters.

Vietnam's government has called the placement of the exploration rig by China in waters near the disputed Paracel Islands a violation of its sovereignty. Both countries have also reported collisions between their ships in the area.

"This extremely dangerous action has been and is directly threatening peace, stability and maritime security and safety," Mr Dung said in Naypyidaw, where he was attending an Asean summit with regional leaders.

Prior to his remarks, anti-China rallies broke out in several major Vietnamese cities. According to Professor Jonathan London at City University of Hong Kong, the Vietnamese leadership uses public protest as a means of expressing extreme discontent with Beijing.

About 1,000 people marched along Ho Chi Minh City streets. Meanwhile, hundreds gathered at a public square in front of the Chinese embassy in the capital city of Hanoi, as police officers watched without interrupting.

There were smaller protests in Danang and Hue in central Vietnam, Tuoi Tre newspaper reported. Protesters carried signs and banners, sang and chanted to protest China's exploration offshore.

"This is the largest anti-Chinese demonstration I have ever seen in Hanoi," said war veteran Dang Quang Thang, 74. "We are here to express the will of the Vietnamese people to defend our territory at all costs. We are ready to die to protect our nation."

Vietnam's tightly controlled state media has covered the oil rig dispute closely and reported on yesterday's demonstrations.

AGENCE FRANCE-PRESSE, BLOOMBERG