U.N. peacekeeping forces circled Haiti's capital Thursday, hours after at least 11 people were killed and scores wounded in violence that marred Secretary of State Colin Powell's (search) visit with Haitian leaders aimed at stopping the country's bloodshed.

Peacekeepers stood guard around the national penitentiary, where inmates rioted Wednesday night, leaving seven dead. Prisoners armed with knives and rocks tried to break free as gunmen outside opened fire, said national prison director Fritzner Pierre.

Pierre said the violence was in reaction to leaked information that prison authorities planned to transfer some inmates. He said the slain inmates were killed by other inmates for refusing to go along with their plan. Many of the prisoners being held there were members of ousted President Jean-Bertrand Aristide's (search) administration.

The prison uprising came after shooting broke out in the Aristide stronghold of Bel Air, blocks away from the National Palace where Powell was holding talks with interim President Boniface Alexandre (search) and Prime Minister Gerard Latortue (search).

Four people were killed in the shooting around Bel Air and scores were wounded.

Gunshots, including several long bursts of automatic weapons fire, were heard in front of the palace shortly after Powell entered with a small U.S. delegation on Wednesday. A palace security official said a shot was fired from a passing car, and U.N. forces guarding the palace returned fire.

Shots were also fired at the U.S. Embassy, according to a U.N. official who spoke on condition of anonymity. It was unclear who the gunmen were.

U.N. peacekeepers, now at 6,000 members, were placed on alert for more violence.

"They have to forcefully take on those armed individuals of the kind who were firing this morning," Powell said late Wednesday.

Violence and political infighting has bloodied Haiti as the one-year anniversary of Aristide's ouster approaches in February. But the country's U.S.-backed government has pledged elections next fall, a goal Powell says can be meet with outside help.

In Washington, State Department spokesman Adam Ereli said that at the time of the first gunshots, Powell was in a holding room at the palace. The incident prompted a change of meeting rooms but otherwise had no effect on Powell's schedule or plans.

Wails of crying families reverberated through the hospital corridors, stained by blood and dirt, and packed with people running from the sounds of gunshots outside the hospital. At least two of the injured were students.

"The security situation is getting worse everyday," said Balthazard Yvonne, 45, whose 18-year-old son was shot Wednesday and undergoing surgery at Port-au-Prince General Hospital.

Powell was once an Aristide supporter but helped arrange Aristide's exile.

Aristide and others claim the United States coerced him to leave. Aristide's followers say Powell signed a plan to remove Aristide because he was viewed as someone whose unpopularity could destabilize Haiti. Washington maintains that Aristide departed voluntarily.

At least 100 people have been killed in political violence since Sept. 30, when pro-Aristide groups stepped up protests demanding his return. Tensions have been mounting between the U.S.-backed government and former soldiers who led the uprising that forced Aristide to flee the country. The ex-soldiers want the reinstatement of the army, which they say Aristide illegally disbanded in 1994. They also want backpay.

Haiti's interim government has accused Aristide of orchestrating the violence from exile in South Africa — a charge Aristide has denied.