Rioters torched and looted about 10 factories during anti-China protests in southern Vietnam in the most serious outbreak of public disorder in the tightly controlled country in years.
The unrest late yesterday at a Singapore-run industrial park followed large anti-China protests by workers at the park and nearby areas.
It shows the danger for authorities in Vietnam as they seek to handle public anger over China's deployment of an oil rig on May 1 in South China Sea waters that Hanoi claims as its own.
The rioters attacked factories they believed to be Chinese but many were Taiwanese owned, said an industrial park management official, who declined to give his name.
This morning, groups of men on motorbikes drove around the complex waving Vietnamese flags and work there was stopped, the official said.
At the height of the protests up to 20,000 people were involved, according to a foreign diplomat briefed on the unrest.
Vietnam reacted angrily to the arrival of the deep-sea oil rig on May 1 close to the Paracel Islands, which are controlled by China but claimed by Hanoi.
It has sent a flotilla of vessels to try and disrupt the rig. Some of the Vietnamese boats have clashed with Chinese ships sent to protect the oil rig.
Over the weekend, Vietnam's authoritarian government gave rare permission for street protests against China in cities across the country.
The ruling Communist Parties in both countries maintain close links and until May 1 had been trying to handle tensions over the territorial disputes quietly.
Vietnamese authorities are normally highly nervous of spontaneous public gatherings of any sort.
Many of the leaders of the anti-Chinese protests are also calling for basic democratic reforms, presenting a challenge to one-party rule.
The stand-off underlines China's intention aggressively to pursue its territorial claims in the South China Sea despite complaints from smaller nations such as Vietnam and the Philippines, which also claim parts of the waters.
The United States, a treaty ally of the Philippines, has called the latest Chinese action "provocative".