Iraqi police say separate bomb attacks have killed at least 26 people and wounded about 30 others in the volatile Diyala province north of Baghdad. Authorities say at least 16 people were killed in one attack and 10 in another, with 27 wounded. As VOA's Deborah Block reports from Baghdad, some of the latest attacks have been directed against Iraqi groups that have turned against the insurgents.

Police say a female suicide bomber targeted a Sunni Islamist group Friday that recently began cooperating with U.S. and Iraqi forces in the fight against al-Qaida militants in Iraq.

A Diyala official says the bomber's two sons had joined al-Qaida and had been killed by Iraqi security forces.

Another suicide bombing took place at a nearby village 30 kilometers east of Baqouba. A driver in a car detonated explosives at a checkpoint.

The attacks highlight the danger for the U.S.-backed groups, which often include former insurgents who have turned against al-Qaida. The groups are credited with helping stem Iraq's violence along with American troops.

Also helping are volunteer Iraqi citizens, who the U.S. military pays about $300 each month, to provide security in their local communities. Ahmed Jamil Hussein is in charge of 180 volunteers in Abu Ghraib, a Sunni area 30 kilometers west of Baghdad.

He says no one believes in al-Qaida because they are liars and kill innocent people. He says al-Qaida has destroyed homes and forced people to leave.

Hussein says the volunteers are helping to drive out al-Qaida militants.

He says there has been a reaction against the militants who have killed peoples' sons. He says there is good cooperation between the volunteers the coalition forces and the Iraqi government.

American officials have also been working with Sunni and Shiite tribal leaders around the country, encouraging them to help stamp out al-Qaida and other militants. The groups include some 60,000 Iraqis, mostly Sunni Arabs.