The Olympic flame relay has arrived for its only stop in the US amid tight security, a day after anti-China protests disrupted its Paris leg.

Extra police will line the torch's route as it travels six miles (10km) through San Francisco on Wednesday.

Seven demonstrators have already been arrested after tying giant "Free Tibet" banners to the cables of the city's Golden Gate Bridge.

China has said "no force" can stop the torch's world relay to Beijing.

International Olympic Committee (IOC) members will discuss the torch relay in meetings in Beijing in the coming days.

IOC President Jacques Rogge said he was "deeply saddened" by the protests in London and Paris and concerned about the San Francisco leg of the flame relay.

The IOC is unlikely to scrap the rest of the international leg of the Beijing torch relay.

What is most likely is that the Beijing international relay will continue, and a decision will be taken after the Games in China about the desirability of holding international relays before future Games, our correspondent says.

Disrupted route

The flame was lit in Olympia, Greece, on 24 March and is being relayed by torch through 20 countries before being carried into the opening ceremony at the Beijing Games on 8 August.

But the torch had to be put out three times in Paris because of the protests. The flame itself was kept alight in a safety lantern.

On Sunday, 37 people were arrested in London as protesters disrupted the torch relay there.

Demonstrators are protesting at China's security crackdown in Tibet after recent unrest against Chinese rule.

Tibetan exile groups say Chinese security forces killed dozens of protesters.

Beijing says about 19 people were killed in rioting.

'Peace and tolerance'

The torch arrived in San Francisco at 0400 local time and was immediately taken to a secret location.

"We treated it like a head of state visit," airport spokesman Mike McCaron told the Associated Press news agency.

One runner who planned to carry the flame on Wednesday has already dropped out because of safety concerns, a spokesman for the San Francisco Olympic Torch Relay Committee said.

Several protests are planned in the city and the police have said they reserve the right to change the relay route if necessary.

US Olympic Committee chairman Peter Ueberroth said in a statement that the event was "an important moment for the city to show its character, hospitality and commitment to peace and tolerance".

Officials have said they want to strike a balance between allowing protesters to express ther views and maintaining public safety.

Police in San Francisco arrested seven people on Monday and charged them with conspiracy and causing a public nuisance.

Three climbers among them faced additional charges of trespassing.

They had scaled the bridge cables to perch 150 feet (46m) above traffic, attaching "Free Tibet" banners and a Tibetan flag.

One of them, Laurel Sutherlin, spoke by mobile phone to reporters.

"If the IOC [International Olympic Committee] allows the torch to proceed into Tibet they'll have blood on their hands," he said.

'A crime'

Chinese state TV said the protesters in London and Paris were a "handful of Tibetan separatists".

Condemning the disruption to the relay, Beijing Olympic organising committee spokesman Sun Weide told reporters the torch relay would continue as planned.

"No force can stop the torch relay of the Beijing Games," he said in Beijing.

IOC press commission chief Kevan Gospar said that this year's 137,000km torch relay will continue as planned, "but certainly, the IOC executive board should review the torch relay programme for the future".

Swedish IOC member Gunilla Lindberg said the protests were "damaging the Olympic movement".

"Using the torch this way is almost a crime. This is the property of the IOC, it is not a Chinese torch."

US Democratic Party presidential hopeful Hillary Clinton has called on President George W Bush to boycott the opening ceremony of the Olympics unless China improves its human rights record.

Mr Bush has said he will attend because he sees the Olympics as a sporting event, not a political one.