Several thousand students, executives and religious leaders gathered outside the US embassy in Beijing.

Duncan Hewitt in Beijing: The mood has turned increasingly ugly

Groups of 100-200 at a time marched past the embassy, stopping to chant slogans such as "Nato fascists" and "Down with Clinton, down with Blair" and to throw stones and bottles.

More than 100 Buddhist monks in orange robes as well as nuns and priests from Beijing's Catholic seminary joined Monday's crowds.

Embassy staff have been told to stay at home but the demonstrations are said to be more orderly than at the weekend.

US Ambassador in Beijing James Sasser: "Unable to leave here now for almost 50 hours"

However, the US ambassador, James Sasser, has not been able to leave the embassy since the protests started, fearing the demonstrators would storm the building.

The scene has been relatively quieter at the British embassy, though its grounds remain littered with debris thrown during Sunday's protests.

Net jam

And the protests are not stopping at the street - angry Chinese are turning to the Internet to voice their outrage.

More than 24,000 protest messages have been registered on a popular chatroom website.

"Our strongest weapon is for the masses to begin a campaign to boycott American goods," wrote one user.

"The anger in our hearts must not lead us to lose reason and curse and beat foreigners when we see them", wrote another called Chinese Kung Fu.

Many of China's most popular sites added additional servers to keep up with demand.

Hackers twice invaded a US embassy website and replaced the home page with text reading "Down with barbarians".

The BBC's Paul Anstiss: China accused Nato of trying to cover up its mistake

On Sunday, angry crowds besieged the US Embassy, demanding revenge for the deaths of three Chinese citizens at the Belgrade embassy.

The British Embassy in Beijing also came under attack, with thousands of angry students pelting the building with stones and paint.

Press attacked

Riot police were unable to stop youths hurling bottles, stones and burning debris around the buildings.

The protesters' anger also turned on foreign news journalists trying to report the events.

The BBC's Jill McGivering: "The unleashed anger could be hard to contain"

A BBC crew in Beijing was beaten and pelted with stones, accused of insulting China.

The strength of feeling in Beijing is likely to work against diplomatic moves currently being pursued by Russian envoy to Kosovo Vitkor Chernomyrdin.

The Chinese press emphasized this, saying anyone who under-estimated the country's indignation would be committing a historical mistake.

State media gave relatively little prominence to news that a fourth person reported missing in the rubble of the embassy was found alive at the weekend, while highlighting pictures of relatives grieving over the bodies of those who died.