The Commonwealth summit in Uganda has been marred by violent clashes between demonstrators and police in the capital, Kampala.
A number of people were hurt in the clashes in Kampala
The violence occurred as opposition-led demonstrators protesting in support of human rights left the area that police had designated for their rally.
Protesters denounced Britain's Queen Elizabeth for meeting President Yoweri Museveni, who they say abuses rights.
There are 50 leaders at the summit who represent two billion people globally.
Police blocked protesters as they tried to march on the city centre, witnesses said.
Police charged with batons and protesters threw stones. A number of injuries were reported.
Main opposition leader Kizza Besigye said: "This is nothing new. This is what we have been living through all this time. This is a police force that does not respect the rights of citizens at all."
The police said they were acting within the law as the demonstrators knew they had to remain in the suburb where the protest was permitted.
The demonstrators carried banners reading: "Queen you are the head of our problems!"
Uganda is the host of the biennial 53-nation Commonwealth Heads of Government Meeting (CHOGM).
The meeting has so far seen the suspension of Pakistan for civil rights violations under its emergency rule.
UK Prime Minister Gordon Brown said: "We will work with Pakistan and the Commonwealth to ensure Pakistan returns to its rightful position in the Commonwealth once the remaining steps are taken."
Pakistan on Friday condemned the decision as "unreasonable and unjustified".
The Queen opened the meeting on Friday by urging Commonwealth leaders to use the "optimism and enthusiasm" of young people as a resource to help solve world problems.
She said: "Young people can and should play a part in the many global challenges that cannot be resolved by older generations alone."
The Queen commended the gathered heads of government for their universal commitment to "respect for fundamental human rights".
Mr Museveni said the Commonwealth could help countries to transform their economies and way of life.
He told the gathering it was the duty of each nation to transform the lives of their rural poor.