Police spray Ugandan opposition party leaders with colored water during demonstrations in the capital Kampala, May 10, 2011. President Yoweri Museveni has vowed to crush the protests and blamed rising food and fuel costs on drought and global increases in oil prices.

Police spray Ugandan opposition party leaders with colored water during demonstrations in Kampala.

Ugandan opposition politician Olara Otunnu, center, stands with his supporters following an attack with water cannons by Ugandan police after he refused to stop his protest march through central Kampala on May 10, 2011 . Ugandan police on Tuesday arrested opposition leader Nobert Mao who attempted to hold a meeting at a public square in the capital Kampala. Mao, who had been briefly detained last week, was dragged into a van by a handful of plain clothed police officers after a standoff with security forces at Kampala's Constitutional Square as opposition leader, Olara Otunnu, retreated after water cannon and tear gas were fired at them to disperse around 20 opposition members.

An Ugandan opposition supporter reacts after police officers fired with water cannons during a protest march through central Kampala.

A military police officer walks past a barricaded road in Kampala, Uganda on April 29. At least one person was killed when Ugandan police fired live bullets and tear gas on Friday to disperse crowds protesting the arrest a day earlier of opposition leader Kizza Besigye, a Reuters witness said.

Ugandan soldiers shoot at demonstrators, who pelt them with rocks from apartment buildings, during riots in Kampala on April 29.

People carry away a woman who fainted after being overcome by teargas during riots in downtown Kampala on April 29.

A plainclothes policeman smashes the car window of opposition leader Kizza Besigye in Kampala, Uganda on April 28.

Another police officer tear gases Besigye in his car.

A policeman goes after a sympathizer of opposition leader Besigye.

Besigye, center, wipes his face while he is dragged away by two plainclothes policemen.

Besigye sits in the Kasangati police station on April 29 after he was detained and attacked with teargas by the police earlier at Mulago roundabout in Kampala.

A Ugandan anti-riot policeman directs Forum for Democratic Change leader Kizza Besigye (center, with bandage) to board a police pick-up track before his arrest in the Kasangati suburb of the capital Kampala on April 18. Ugandan opposition leader Besigye was arrested on Monday during a protest against high food and fuel prices in the capital Kampala, police said.

Ugandan security agents arrest Kizza Besigye center) in, Kasangati, Kampala on April 18.

Kizza Besigye (center) sits on the back of a police pick-up truck after he was arrested in Kasangati, Kampala on April 18.

Ugandan police beat up a protester on Thursday, April 14, in Kampala, Uganda. Witnesses in Uganda say police fired tear gas into a hospital during a skirmish with stone-throwing protesters.

Supporters of Uganda's Forum for Democratic Change (FDC) leader Kizza Besigye participate in a protest along the road in the Kasangati suburb of the capital Kampala on Thursday.

Uganda's opposition leader Dr. Kizza Besigye (on stretcher) is taken to hospital in Kampala on Thursday. Besigye was shot in the arm when police on fired tear gas and rubber bullets to stop groups of protesters from marching towards the capital Kampala, the Red Cross said.

People queue to cast their vote at a polling centre in Rushere, Kiruhura district, about 185 miles west of the capital Kampala, on Feb. 18. Ugandans voted in an election on Friday expected to extend President Yoweri Museveni's time in power to three decades but which could turn nasty because the opposition wants street protests if the poll were deemed rigged.

A Ugandan electoral commission official serves a woman at a polling centre in Rushere, Kiruhura district on Feb. 18.

Women wait in line to vote at the Mukwano polling station in central Kampala, Uganda on Feb. 18.

Opposition leader Kizza Besigye addresses to his supporters during the closing rally of his Presidential campaign in Kampala on Feb. 16.

Supporters of opposition leader Kizza Besigye ride wildly on a motorcycle in a soccer pitch ahead of Besigye's convoy through town during the last day of the Presidential campaign on Feb. 16 in Kampala.

Tens of thousands of supporters of Uganda's ruling National Resistane Movement (NRM) and its leader President Yoweri Museveni wave flags as cheer during a rally in the capital Kampala, on Feb. 16, the last day for the Presidential election campaign.

A supporter of opposition leader Kizza Besigye looks at the stage at the closing rally for Besigye's campaign in Kampala on Feb. 16, during the last day of campaigning for the Presidential elections.

Uganda's President Yoweri Museveni and First Lady Janet wave to supporters on arrival at the last campaign rally in the capital Kampala on Feb. 16.