Police in San Francisco have stepped up security ahead of the Olympic torch procession through the city in a bid to prevent an embarrassing replay of the attempted torch grabs in Paris and London earlier this month.

Police plan to shield the runners as they carry the Olympic torch up and down the central waterfront with no fewer than three layers of protection - cops on foot jogging at their side, cops on bicycles and cops on motorcycles.

Department insiders say the police will even have boats stationed along the waterfront route in case things get really out of hand.

"The idea is if there is some kind of mass sit-in that blocks the road, then they can just put the torch on a boat and move around it," said one City Hall source, who asked not to be named because he was not authorized to discuss security plans.

All in all, some 700 officers in uniform are expected to be posted along the route – the exact details of which are still unknown. In a bid to outwit protesters who may disrupt the event, the police have a number of contingency routes planned. Even the runners who will carry the flame have yet to be told what the final route will be.

With the opening ceremony of the Olympic Games in Beijing just months away, thousands of pro-Tibet campaigners – angry at China's occupation of Tibet - turned out in force to disrupt both the London and Paris stages of the torch run.

San Fran Police are adamant that what happened in Paris on Monday - where the run was cut short and the Olympic torch was whisked away on a bus – won't happen on this leg of the Olympic flame world relay.

"We're not going to let it happen," said one police commander whose troops will be among those on the front line.

But for all the planning and all their confidence, police acknowledge that a smooth run is no sure thing.

Authorities were briefed by the police official in charge of keeping order for London's torch run on Sunday. One San Fran police source said: "the guy told us they didn't just have a handful of protesters trying to get the torch like it might have looked on TV. They had 100 of them, and it was nonstop."

The article Olympic torch arrives in San Francisco originally appeared on 999 Today