Bunia, Congo ? The last two main militia groups in Congo’s most troubled province agreed to disarm in exchange for amnesty and army positions, officials said Thursday as violence erupted in the capital, reportedly killing seven people ahead of historic weekend elections.

Police fired tear gas at a campaign rally in Kinshasa that turned violent after a fire broke out at a camp for militiamen loyal to rebel-leader-turned presidential candidate Jean-Pierre Bemba.

A mob attacked and killed one soldier who allegedly fired into the crowd near the rally that drew 20,000 Bemba supporters to a stadium in the capital. Crowds of angry youths ran through the streets, burning and looting a nearby church where they saw posters bearing the image of President Joseph Kabila.

The U.N. said two police officers were killed in the mayhem, and Bemba’s officials said three civilians also died. A fire also broke out at the home of Bemba’s bodyguard in which two children died, witnesses told The Associated Press.

Sunday’s vote will be Congo’s first democratic presidential election since independence from Belgium in 1960. Many hope the poll will bring an end to years of corruption and conflict since back-to-back wars that began in 1996.

Though a peace deal ended most fighting in 2002, much of the east, including the northeastern Ituri province, remained lawless, wracked by sporadic fighting. Clashes between rival militias in Ituri alone have left more than 50,000 dead since 1999.

Supporters of Democratic Republic of Congo presidential candidate Jean-Pierre Bemba cheer in the Tata Raphael stadium in Kinshasa during a rally for the Congolese Liberation Movement. More than 20,000 attended Thursday's rally addressed by Bemba.

The militias’ agreement to lay down arms marks a momentous breakthrough that could end fighting in the northeast and ensure a peaceful presidential vote.

The two militia groups are the 10,000-strong Congolese Revolutionary Movement, a coalition of militia groups formed in December under Mathieu Ngudjolo and blamed for much of Ituri’s recent violence, and the smaller Cobra Matate militia, which numbers about 500.

“We want there to be elections, we want to stop the fighting. We want peace,” Ngudjolo told The AP on a hill overlooking Bunia, where he sat with weapons and 250 fighters.

Militia fighters still have to follow through and actually lay down their arms, something that has proved difficult in the past. Though about 3,500 voluntarily disarmed over the past month, no disarmament date has been set for others to hand in weapons.