Protesters crash Olympic torch party in London

LONDON (Reuters) - Thousands of protesters waving Tibetan flags and shouting "Shame on China" disrupted the Olympic torch's marathon relay through London on Sunday, billed as a journey of harmony and peace.

The flame survived a 31-mile (50-km) obstacle course of lurching demonstrators, an unexpected protective trip on a double-decker bus and even a fire extinguisher to arrive in Greenwich, southeast London, where double gold medalist Kelly Holmes lit up the Olympic cauldron.

But chaotic scenes of police scuffling with anti-China campaigners and images of a triple ring of British police and Chinese officials guarding the torch throughout the all-day relay will embarrass Chinese and Olympic officials.

The torch is on its way to the 2008 Games in Beijing from August 8 to 24. The next Summer Olympics are in London in 2012.

The Olympic flame is supposed to be a symbol of peace and unity and the relay was meant to be a celebration.

One man got his hands on the torch before being wrestled to the ground by police, who arrested at least 35 people.

Martin Wyness and Ashley Darby were detained after trying to put out the flame with a fire extinguisher.

"China has no right parading the Olympic torch through London. The relay ... is nothing more than an elaborate propaganda tool to cover its appalling human rights record," they said in a statement.

Television personality Konnie Huq said she had been "a bit bashed about" when a man tried to rip the torch from her hands: "I was determined to hang on, it was all a bit of a shock."

The intensity of the protests against China's crackdown in Tibet, its failure to stop the bloodshed in Sudan's Darfur region and its human rights record forced last-minute changes to the transport used for the lengthy relay.

Police were forced to rush the flame onto a double-decker bus in Fleet Street when about 100 protesters tried to seize it.

Flanked by police vans and officers running alongside, the bus crawled along to St Paul's Cathedral as spectators, who had expected to see the torch paraded on foot, looked on bemused.

BROWN UNDER FIRE

Earlier, outside Prime Minister Gordon Brown's Downing Street office, 1,000 anti-Beijing protesters traded slogans with China supporters who waved flags and banged drums.

Brown greeted the torch behind Downing Street's closed steel gates in front of a vetted crowd as protesters scuffled with police.

Opposition politicians and campaigners criticized Brown for taking part. Olympics Minister Tessa Jowell said Britain was endorsing Olympic principles and sport and not China's record.

"The welcome of the Olympic torch to London is not the same as condoning the human rights regime in China or condoning the treatment of Tibet," she told BBC Television.

International Olympic Committee President Jacques Rogge said in March at the torch's lighting in Olympia, Greece, the relay was meant to be "a journey of harmony, bringing the message of peace to people of different nationalities, cultures and creeds".

Instead, the protests and arrests began from the start of the relay at Wembley Stadium, the national soccer ground.

Chinese security forces have locked down Tibet and neighboring provinces to quell anti-Chinese protests and riots that started in mid-March.

China has said the Games should not be politicized and the IOC has vigorously defended its policy of non-involvement in politics.

The flame now moves on to Paris.

(Additional reporting by John Joseph, Eric Onstad, Writing by Katherine Baldwin; editing by Matthew Jones)