Police were forced to bring in reinforcements to marshal the Olympic torch relay through London after a series of protests along the 31-mile route by demonstrators angered at China's human rights record. More than 35 people have been arrested, all for public order offences.

Throughout the day there were incidents and flashpoints, the most serious occuring in Ladbroke Grove when a Free Tibet protester slipped through a 50-strong pack of British police and Chinese security guards before attempting to wrestle the Olympic flame from Blue Peter TV presenter Konnie Huq. The episode was brought to an end when the protester was bundled to the ground.

Two others were also taken away after trying to put out the flame with a fire extinguisher in Holland Park, and the procession was later forced into a temporary halt as the torch made an unscheduled switch to a bus while police pondered how to safely negotiate a crowd of protesters at Fleet Street. The move briefly prevented further disruption but negated the spectacle, with the torch bearer completely hidden from the throngs lining the route from Wembley Stadium to Greenwich.

At several times during the day protesters threw themselves in front of the runners and there were also scuffles between police and demonstrators. At one point, the torch procession even went the wrong way down a one-way street and was forced to turn round.

When the bus travelled along Oxford Street, human rights campaigner Peter Tatchell stopped it in its tracks by jumping into the road holding a sign saying "Free Tibet, free Hu Jia". "The arrest last week of human rights activist Hu Jia shows that China is not fulfilling its human rights commitments which were part of the deal for them to get the Olympics," Mr Tatchell said. "At the very least, world leaders should boycott the opening ceremony and athletes should wear Tibetan flags when they go on the podium to receive their medals." Mr Tatchell said he was detained by police but released with a warning.

Outside Downing Street, several demonstrators attempted to run towards the torch - with some trying to jump the barriers lining the pavement - as former Olympic pentathlon champion Denise Lewis took the flame. Many were bundled to the floor by police, who were out on foot, on bicycles, and mounted on horseback. The crowd reacted noisily, booing and whistling and shouting protests.

Thousands of peaceful protesters, many of them wearing Tibetan flags, also waved banners proclaiming "Torch of shame", "Stop the killing in Tibet", "No Olympic torch in Tibet" and "China talk to Dalai Lama". Helping to lead the chants was Buddhist monk Ngawang Khyentse, who said: "We can't just remain silent. We have no other choice than to protest because there is no other voice for Tibetans inside Tibet, so we have to speak out for human rights. We are not asking for a boycott of the games, although there are many different views. We are asking for pressure to be put on the Chinese government to help the situation in Tibet."

Tessa Jowell, the minister for the Olympics, said that despite the protests it would have been a "great mistake" not to have gone ahead with the relay. She added: "I hope that the message that will go round the world is that, yes, there are many citizens of the UK who feel very strongly about China's human rights record, there are people in the UK who feel very strongly about the importance of dialogue with the Dalai Lama, and that in the UK we cherish the right to lawful and peaceful protest which, by and large, is what we have seen today."

Jowell's views were echoed by Conservative leader David Cameron, who acknowledged that many people were "very unhappy" about what was happening in Tibet, but rejected calls for a boycott. "I don't think we are at the stage yet where we should be considering a boycott," he said. "I think having a policy of robust engagement with China is right."

Earlier Britain's greatest Olympian, the five-times rowing champion Sir Steve Redgrave, took the first leg of the relay before passing the Olympic flame to 16-year-old schoolgirl Cheyenne Green at a frosty Wembley Stadium. The British Olympic Association chairman, Lord Moynihan, told crowds: "The power of this Olympic torch will shine a light on the recesses of the host city and China's record."

However, Tom Porteous of Human Rights Watch has urged the government to do more to bring China's human right's record in Tibet to account. "The prime minister should use this occasion to speak publicly about China's Olympian abuses," he said. "The main thing the Olympic torch relay illuminates in Britain is the government's lack of public strategy to address Olympic-related human rights issues in China in advance of the Beijing Games."