At least 25 people were arrested here on Sunday as they tried to disrupt the Olympic torch parade's 31-mile-long journey through the British capital.

Protests over China's human rights record in Tibet began soon after rower Sir Steve Redgrave started the torch relay from the Wembley Stadium.

Demonstrators tried to snatch the torch from former Blue Peter host Konnie Huq, and after an unpublicised change to the route, China's Ambassador to the United Kingdom Fu Ying carried the torch through Chinatown, amid fears that her presence could be a flashpoint.

A small contingent of pro-China supporters also tried to make their voices heard, waving Chinese and Olympic flags and calling for "one China".

There were chaotic scenes in Whitehall as as former Olympic pentathlon gold medallist Denise Lewis took the flame to Downing Street. Prime Minister Gordon Brown greeted the torch outside his official residence at 10, Downing Street despite coming under pressure to boycott the parade and the Beijing Olympics opening ceremony.

Ahead of the procession, Liberal Democrat leader Nick Clegg branded Brown's participation as "wholly inappropriate".

A mobile protective ring was mounted round the torch as it was carried by bus, foot, boat and light railway past some of London's most iconic sights.

The BBC quoted Metropolitan Police Commander Jo Kaye, as saying that: "The Met has clearly stated in the build up to this event that we will facilitate lawful protest, however we will not tolerate continued attempts to breach the safety security and safe passage of the torch and its bearers."

Police stepped in when protesters tried to snatch the torch from Huq, who admitted that she was hurt during the scuffle.

"I believe in the Olympic values, the Olympic ideals... it's just unfortunate that China has such a terrible track record when it comes to human rights and they are the host nation," she said.

Those taking part in the relay include 10 Olympic champions, 18 schoolchildren and public figures such as news reader Sir Trevor McDonald and musician Vanessa Mae.

Double Olympic champion Dame Kelly Holmes will run the last stage of the route to complete the relay before lighting the Olympic cauldron in front of 5,000 spectators.

The flame will complete the London leg of its journey with a finale event at the O2 Arena headlined by the Sugababes. It will then leave for Paris.

The torch was lit in Olympia, Greece, last week and will go through 20 countries before being carried into the Beijing Games opening ceremony on August 8 this year.