BAGHDAD (AP) – U.S.-backed Iraqi forces swept through a central Baghdad slum Sunday, disarming Sunnis from a government-allied paramilitary group to quell a two-day uprising launched to protest the arrest of their leader.

At least four people were killed and 21 wounded in the two days of fighting between government troops and the Awakening Council in Fadhil, a ramshackle warren of narrow, fetid streets on the east side of the Tigris River where al-Qaida once held sway.

The confrontation in Fadhil could be explosive if it leads to a split between the Shiite-led government and the Awakening Councils, made up of Sunnis who abandoned al-Qaida and joined forces with the Americans to fight the insurgents.

Distrust runs deep between the Shiite-led government and the Awakening Councils, which the U.S. calls Sons of Iraq, because many of them are ex-insurgents. There have been fears that some fighters may return to the insurgency if they feel threatened by the government.