Iraqi troops backed by armored vehicles patrolled deserted streets of a central Baghdad neighborhood Sunday after the arrest of a Sunni leader who had broken with Al-Qaeda sparked a gunfight that killed four people and wounded 15. A police official said five Iraqi soldiers were missing after the fighting, which erupted when police and soldiers arrested Adil Al-Mashhadani, the head of an Awakening Council group in Fadhil, a Sunni enclave on the east bank of the Tigris River. The official spoke on condition of anonymity because he was not supposed to release the information. Awakening Councils, or Sons of Iraq, are Sunni security volunteers who broke with Al-Qaeda and joined forces with the Americans to drive Al-Qaeda from their areas. The rise of the Awakening Councils is considered a key move in turning the tide against the Sunni insurgency. But Shiite political leaders have never fully trusted the Awakening Groups, many of whom were ex-insurgents. How the Shiite-led government deals with the Sunni security volunteers is widely seen as a test of its ability to win the loyalty of disaffected Sunnis – an essential step in forging a lasting peace in Iraq. Al-Mashhadani was arrested along with an aide for alleged terrorist activity, Iraqi military spokesman Maj. Gen.Qassim Al-Moussawi said without elaborating. He said the troops had a warrant issued by an Iraqi judge. About a half hour after the arrest, heavy gunfire broke out in Fadhil, sending residents fleeing the streets, witnesses said.