China President Hu Jintao started a state visit to the United Kingdom today amid noisy protests from human rights groups outside London's Buckingham Palace.
Mr Hu and his wife are attending a banquet in the presence of the Queen at Buckingham Palace, and security has been beefed up around the royal residence.
Protesters have vowed to "dog" the Chinese leader's trip to London.
Demonstrators from the Free Tibet Campaign, which calls for an end to Chinese occupation of Tibet, gathered along the Mall, waving Tibetan flags and banners, for the ceremonial welcome by the Queen and the Duke of Edinburgh on Horse Guards Parade.
They will stage further protests outside the palace this evening to coincide with the grand state banquet.
China has been condemned by human rights campaigners for executing hundreds of people every year and for failing to stop torture.
Amnesty International called on Mr Blair to raise human rights issues during the visit - Mr Hu will meet Mr Blair tomorrow. - and it expressed concern over the continuing detention of Tiananmen prisoners 16 years after the events in the square.
PA