ABIDJAN, Ivory Coast (AP) _ U.N. peacekeepers battled attackers trying to enter their compound in Ivory Coast's government-held south Wednesday, leaving at least four dead and 10 wounded in a third day of unrest in the divided nation.

Capt. Gilles Combarieu, a U.N. military observer, said the Bangladeshi troops exchanged fire with gunmen in the government-held town of Guiglo. All U.N. employees later withdrew from the town.

``They had to defend themselves,'' Combarieu said, adding that 200-300 U.N. peacekeepers and staff were moving north toward a more heavily guarded buffer zone separating government and rebel fighters.

Residents reached by telephone in Guiglo, near the Liberia border, said rioters were looting the offices of humanitarian groups.

Combarieu said about 70 U.N. peacekeepers and all other U.N. staff in the nearby town of Douekue also were evacuating after threats of violence.

In the main Ivory Coast city of Abidjan, peacekeepers inside the country's U.N. headquarters fired into the air and launched tear gas grenades at demonstrators for a second straight day Wednesday, keeping about 1,000 protesters at bay, he said.

The west African nation has been on edge since President Laurent Gbagbo canceled planned October elections, blaming rebels who control the north and refuse to disarm. Afterward, the United Nations and the African Union endorsed a one-year extension of Gbagbo's five-year mandate, which rebels and opposition leaders fiercely opposed.

Gbagbo now leads a one-year government of national unity, but he has diminished executive powers and is supposed to hold elections by October.

The street protests and clashes erupted after a U.N.-backed mediation group recommended over the weekend that the parliament's expired mandate not be renewed.

The parliament is filled with Gbagbo supporters and is viewed as his last bastion of power. The mediators' decision angered Gbagbo supporters.

On Tuesday, the president's ruling Ivorian Popular Front said it was withdrawing from the peace process and no longer would cooperate with the transitional government composed of rebel, opposition party and ruling party ministers. It also demanded U.N. forces leave the country.

The United Nations so far has suffered the brunt of the protesters' ire.

Secretary-General Kofi Annan condemned the violence Tuesday, saying it threatened the nation's fragile peace.

On Wednesday, a spokeswoman for the U.N. force, Margherita Amodeo, said four non-U.N. personnel died in the gunfight in Guiglo.

A doctor at the town's main hospital said there were two dead bodies with bullet wounds at the morgue and reports of three more corpses in Guiglo's streets.

Ten others were treated for gunshot wounds, the doctor said on condition of anonymity because he was not authorized to speak to reporters.

On Wednesday, Gbagbo supporters blocked streets across Abidjan. Businesses shut down across the city amid fears of a return to all-out violence in a country divided between government and rebel control after a 2002-2003 civil war.

Aides to Nigerian President Olusegun Obasanjo said the leader of Africa's most-populous nation would make an unplanned trip to Ivory Coast Wednesday to meet with Gbagbo. Obasanjo has played a crucial role in mediating many West African crises.

While Gbagbo has officially banned street demonstrations, his security forces appeared to do little to disperse government supporters erecting burning barricades in streets and besieging U.N. offices across the cocoa-rich south.

The French army chief of staff, Gen. Henri Bentegeat, called for U.N. sanctions against Ivory Coast on Wednesday on Europe-1 radio, saying both sides have shown they are unwilling to resolve the conflict.

France retains economic interests in Ivory Coast, its former colony, and has peacekeepers in the country alongside a U.N. force. In all, there are 10,000 peacekeepers in Ivory Coast.

There were no reports of strife from the rebel-held north, where insurgent leaders accuse Gbagbo of orchestrating the protests to undermine a new transitional government.

``It's an insurrection against the transitional government organized by Gbagbo and (his political party) to bring power back into their hands,'' rebel spokesman Sidiki Konate said.

Officials at the presidency could not be reached for comment.

In the western port city of San Pedro, protesters hurled firebombs into a U.N. office, though no injuries were reported.