Hundreds of people have been marching through central London to protest against China's violent crackdown against demonstrators in Tibet.
Protesters are demanding action over repression in Tibet
Protesters marched from Regent's Park to Trafalgar Square, staging a rally in front of the National Gallery.
The marchers, including many exiled Tibetans, also sang the Tibetan national anthem at the Chinese Embassy.
Protesters said a meeting due between Gordon Brown and spiritual leader the Dalai Lama must produce solid action.
Chonpel Tsering, a Tibetan who has been in the UK since 1982, said it was crucial for independent observers and journalists to be allowed into his country in order to tell the truth about what is going on there.
He said: "This fundamentally is to show the support of Tibetans and other supporters in the UK for the people inside Tibet who have taken the brave and bold decision to rise up against the Chinese, who have occupied their country.
"We know some have been killed and hundreds, perhaps thousands have been arrested."
He welcomed Prime Minister Gordon Brown's announcement earlier this week that he would meet with Tibet's spiritual leader, but said the meeting should have happened sooner and that it must be more than a "photo opportunity".
Mr Tsering said: "What we want to hear from Gordon Brown is that the meeting will be more than gesture politics. Something concrete must also come out of it."
The march was organised by Tibet support groups in the UK to show solidarity with the protesters in Tibet and pressure international leaders to speak out against China.
Chinese authorities have issued a list of 21 people wanted for their alleged role in anti-China riots in the Tibetan city of Lhasa last week.
China has said that 19 people were killed in the Lhasa riots, which later spread to other Tibetan areas.
But Tibetan exiles say that nearly 100 have been killed by the Chinese security forces.