U.N. peacekeepers in armored vehicles rolled through nearly deserted streets Friday in Haiti's capital, where shops were closed for fear of violence on the 10th anniversary of the first return from exile of the ousted president, Jean-Bertrand Aristide.

Burning tires smoked in Bel Air, a slum stronghold of Aristide loyalists who barricaded streets with wooden market stands and debris. Residents said gunshots rang out occasionally.

Aristide backers are demanding his return to the Caribbean country from his current exile in South Africa as they mark his restoration to power in 1994 after intervention by 20,000 U.S. troops ended three years of brutal military rule.

Business leaders called for a "day of protest against terrorism" Friday following two weeks of shootouts and beheadings that have killed at least 48 people. Many Haitians heeded the call for a shutdown, staying home while banks, stores and gas stations were secured. Police stood watch at intersections.

U.N. peacekeepers have taken over from the U.S. Marines who arrived on Feb. 29, the day Aristide fled a rebellion by former soldiers of the army that ousted him in 1991 and that he disbanded in 1994.

Heavily armed ex-soldiers based in Port-au-Prince said Thursday that reinforcements had been arriving from all over the country to help end the present violence.

The United States urged the departure of all nonessential personnel and family members working at its embassy in Port-au-Prince, which was shut Friday. The State Department also upgraded its travel warning for Haiti, saying police were ineffective and peacekeepers were not fully deployed.

It warned against "the potential for looting; the presence of intermittent roadblocks set by armed gangs or by the police; and the possibility of random violent crime, including kidnapping, carjacking and assault."