HANOI, Vietnam >> A 1,000-strong mob stormed a Taiwanese steel mill in Vietnam and hunted down Chinese workers, killing one, attacking scores more and then setting the complex alight, Taiwanese and Vietnamese authorities said Thursday, further inflaming tensions between Hanoi and Beijing as they square off against each other in the disputed South China Sea.

It was the first deadly incident in a wave of anti-China protests triggered by Beijing’s deployment of an oil rig in the long-disputed seas on May 1. Vietnam is angrily demanding that China remove the rig and has sent ships to confront it and a flotilla of Chinese escort ships, triggering fears of possible conflict.

Taiwanese companies, many of which employ Chinese nationals, have borne the brunt of the protests and violence, which is posing a challenge to the authoritarian government, which prides itself on maintaining peace and security. Prime Minister Nguyen Tan Dung said peaceful protests over the last few days were "legitimate," but that anyone involved in violence should be punished severely.

Nervous Chinese expatriates were fleeing by land and air. Cambodian immigration police said 600 Chinese crossed into Cambodia over the land border in southern Vietnam on Wednesday, and that others were arriving Thursday. Taiwan’s China Airlines was adding two additional charter flights from southern Vietnam’s Ho Chi Minh City, according to Taiwan’s Central News Agency.

In Beijing, Foreign Ministry spokeswoman Hua Chunying said China was "greatly shocked and concerned."

"We urge the Vietnamese government to earnestly assume responsibility, get to the bottom of the incident, punish the perpetrators harshly, and pay compensation," Hua said.

The riot took place at a mill in Ha Tinh province in central Vietnam, about 350 kilometers (220 miles) south of Hanoi. It followed an anti-China protest by workers at the complex, operated by the conglomerate Formosa Plastics Group, one of the biggest foreign investors in Vietnam, according to Taiwan’s top representative in the country, Huang Chih-peng, and police.

Huang, who spoke to a member of the management team at the mill, said rioters lit fires at several buildings and hunted down the Chinese workers, but did not target the Taiwanese management. He said the head of the provincial government and its security chief were at the mill during the riot but did not "order tough enough action."

He said he was told one Chinese citizen was killed in the riot and around 90 others were injured. Ha Tinh’s deputy police chief, Bui Dinh Quang, said the situation was "stable" on Thursday and that none of the injured, which he put at 141, had life-threatening injuries.

Anti-Chinese sentiment is never far from the surface in Vietnam, but has surged since Beijing deployed the massive deep sea oil rig in disputed waters about 240 kilometers (150 miles) off the Vietnamese coast, close to the Paracel Islands. The government protested the move as a violation of Vietnam’s sovereignty and sent a flotilla of boats, which continue to bump and collide with Chinese vessels guarding the rig.

Earlier this week, mobs burned and looted scores of foreign-owned factories at industrial parks in southern Vietnam near Ho Chi Minh City. They believed they were Chinese-run, but many were actually Taiwanese or South Korean. Authorities said they had detained more than 400 people.

There is no easy solution to the standoff in sight.

"Either the oil rig stays, and the Vietnamese leaders concede that they were unable to defend the nation from a serious incursion on its sovereign rights, or China backs down, moves the ship out and internationally concedes that its claims to the Paracel Islands are unjustified or, at least, in need of further discussion," said Jason Morris-Jung from the Institute of Southeast Asian Studies. "Both scenarios are hard to imagine."

Low wages, especially compared to next-door China, and a reputation for safety compared to some other developing nations in Asia, have led to a surge in direct foreign investment in Vietnam over the last years. China is Vietnam’s biggest trading partner, and Taiwan is its fourth-biggest investor.

Minister of Planning and Investment Bui Quang Vinh said 400 factories had been damaged since the unrest began this week, and that worker protests had broken out in 22 of the country’s 63 provinces. "The investment image that we have been building over the past 20 years is turning very ugly," he told parliament, according to an account in the state-run Labor newspaper.

Willy Lin, who heads a Hong Kong trade group representing knitwear manufacturers and exporters, said investors were hoping it was "one-off incident." ”If this madness continues and spreads out in the next couple of days to other parts of Vietnam, definitely it will have a very damaging effect on exporters, because they might not be able to commit to their delivery day," he said.

Hong Kong-based contract clothing maker Lever Style, which started outsourcing production to Vietnamese factories three years ago, has sent some Chinese quality assurance and technical support staff working at those factories back to China as a safety precaution, said CEO Stanley Szeto.

"You always have these little hiccups, no matter where you go," Szeto said. "Other than our staff, we’re not really affected."

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Associated Press writers Kelvin Chan in Hong Kong, Sopheng Cheang in Phnom Penh, Cambodia, Christopher Bodeen in Beijing and Tran Van Minh in Hanoi contributed to this report.