The city officials, fearing skirmishes between anti- and pro-Chinese demonstrators lined up about 10-km-long declared route, took the flame straight to San Francisco International Airport and put it in the plane even without the official closing ceremony.

No one, not even reporters and most of the security personnel, were told about the change of route which angered thousands of Chinese-Americans some of whom had come over long distances to cheer the flame, disappointed general public and gave some satisfaction to pro-Tibet protestors who called it a "cowardly act."

But in the process, the city saved the type of situation Paris and London witnessed and to be on the safer side, it also cancelled the public closing ceremony where protesters had taken positions.

\The torch was lit at McCovey Cove behind the schedule and shortly afterwards, the first torchbearer, flanked by Chinese security personnel in blue dress and American police, took the flame to a warehouse and failed to reappear for a while, leaving people and the media wondering what had happened.

The flame remained inside for more than half an hour and then it was taken in a van under heavy security to a location more than two kilometres away in the opposite direction to avoid those protesting China's crackdown in Tibet.

After the restart of the relay, which was cut to merely three miles from the original six, police motorcycle convoys surrounded the runners on both sides, which kept people from getting into the streets.

However, by the time the flame reached the waterfront, some protesters managed to catch up with the torchbearers.

In fact, one of the torchbearer turned out to be a supporter for Tibetan independence. Police yanked the torch away from Majora Carter and pushed her into the sidewalk after she pulled out a 'Free Tibet' flag hidden in her shirt.

"They pulled me out of the race, and then San Francisco police officers pushed me back into the crowd on the side of the street," said Carter, 41, who arrived from New York.

There was a heavy police and FBI presence to keep apart the protestors as the torch made its way through the streets of San Francisco, which is the only stop for the torch in North America. The city was chosen to host the relay, in part, because of its large Chinese-American population.

Most Chinese-Americans said the Games should not be politicised as the Olympics are celebration of sports.

San Francisco's Mayor defended the decision to reroute the relay. Gavin Newsom said in a radio interview that concern about attacks on torchbearers prompted a decision to dramatically alter the relay route and sneak the torch past crowds waiting near the starting point.

"I'm sorry. I wanted this to be a perfect event. I want this world to be a perfect world. I want what happened in Paris not to have happened. I want what happened in London not to have happened," he said.

Demonstrators carrying placards reading "Stop Genocide In Tibet" and also denouncing China for not doing enough to pressurise its close ally Sudan over the Darfur violence started gathering hours before start of the relay.

The demonstrators who were getting information as to where the flame was over cell phones tried to reach altered route but mostly failed.

Police had put up strong barricades on the original route but there were no barriers on the route that the flame took apparently to keep it secret from the demonstrators.