In the largest raid, US-led forces hunted for a "foreign terrorist facilitator and al-Qaeda in Iraq leader" in the restive town of Yusufiyah south of Baghdad, the military said in a statement.

As the troops neared the building, gunmen opened fire on them, prompting US forces to call in an air strike which killed five terrorists and sending others fleeing to an adjacent building, where seven of them were then detained.

The military said a boy was injured in the operation and later treated at a military hospital.

During a separate operation north of Baghdad, gunmen opened fire on US aircraft patrolling the area. The aircraft returned fire, killing three militants and injuring a fourth, the statement said.

Soldiers detained three more militants following the battle and arrested another 11 alleged militants in separate operations south of Baghdad and in the central Salaheddin province, a Sunni insurgent hotbed.