Anti-China violence subsided in Vietnam on Friday after the prime minister called for calm and its de facto ambassador to Taiwan apologized, but the United States said China's "provocative" actions in maritime disputes were dangerous and had to stop.

Thousands of people attacked businesses and factories in Vietnam's industrial parks earlier in the week, targeting Chinese workers and Chinese-owned businesses after Beijing parked an oil rig in a part of the South China Sea claimed by Hanoi. Many Taiwanese-owned firms bore the brunt because the crowds believed they were owned by mainland Chinese. About 1,000 people reportedly have already been arrested and indicted.

The riots risk derailing a major driver of the country's economic growth — industrial parks account for more than 30 percent of Vietnam's exports and have attracted around $110 billion in foreign direct investment.