By Carmen Cheung in Beijing, Pamela Pun and agencies
UP to 100,000 angry demonstrators besieged the United States Embassy in Beijing for a second day of rock-throwing demonstrations against Nato's bombing of the Chinese Embassy in Yugoslavia.
Similar protests were staged in more than two dozen mainland cities.
In Chengdu, demonstrators set the US consulate on fire overnight on Saturday. The consul's residence was badly damaged by fire and windows were broken, but no Americans were injured.
In Beijing, most of the windows of the US embassy had been shattered by protesters hurling rocks and water bottles. At one time angry students threw Molotov cocktails into the embassy's yard.
The embassy said it had lodged a protest against the attacks and appealed for better security.
The mission said the US embassy in Beijing and consulates across the mainland would close on Monday and Tuesday and Americans in the country were advised to stay home on both days, the official said.
US Ambassador James Sasser complained on CBS television that personnel at the Beijing embassy had been ``hostages'' for the past 48 hours as angry demonstrators vented their anger.
The situation prompted Vice-President Hu Jintao to make a statement vowing to protect foreign nationals on its soil and appealed to protesters to remain calm. However, he also pledged strong support for the student-led anti-Nato demonstrations.
``China firmly supports and protects in accordance with the law, all legal protest activities against the US-led Nato attack on the Chinese Embassy in Yugoslavia,'' Mr Hu said in a televised statement, on behalf of President Jiang Zemin.
``China will protect foreign diplomatic mission and institutes, foreign nationals in China and foreigners who come to China for economic, trade, educational and cultural activities, according to (international and Chinese) law.''
Mr Sasser also expressed sorrow at the ``tragic mistake'' of Nato's bombing of the Chinese embassy in Belgrade.
Ignoring such apologies, including ones from US President Bill Clinton and other Nato leaders, up to 100,000 demonstrators besieged the US embassy in the biggest protest seen in Beijing since the 1989 pro-democracy movement.
The mission was splattered with red, black and blue paint and rocks, stones and water bottles littered the grounds.
Protesters set banners on fire and hurled them over the heads of the police into the compound. They failed to set the building alight. Mr Sasser's house was also besieged by furious demonstrators.
Security there was thinner and the police mostly stepped aside as the crowd took aim at its windows.
Scores of military vehicles could be seen lining the streets of a main artery _ barricaded by police _ running into the embassy district.
The protests, originally led by students, were joined by ordinary people beginning late on Saturday, bringing traffic on main roads to the district to a virtual standstill.
Hundreds of armed police manned every intersection in the area, often restraining thousands of onlookers from joining the protests.
Tens of thousands of demonstrators marched past the US and British embassies and ambassadors' residences, throwing stones, burning US flags and shouting slogans like ``Down with US imperialism''.
In Chengdu, about 2,000 protesters tried to break through the consulate gate, but police pushed them back.
Cornelis Keur, the US consul general in Chengdu, was forced to flee his residence after midnight when flames were spotted shooting from the roof of his two-storey residence, US embassy officials said.
Police dispersed the protesters with tear gas, and the small number of staff members and their families were moved to another part of the city, the spokesman said.
In Guangzhou, the US fastfood chain McDonald's became the target of demonstrations.
The People's Liberation Army also joined in condemning the Nato bombing of the Chinese embassy. ``The military forces were shocked and enraged by the Nato attack,'' Xinhua said. The report said the military ``are determined to strengthen national defence and modernise the Chinese army''.