Iraqi hospital officials say clashes in Sadr City have killed 11 men and wounded 19 others.

The clashes come even though Iraq’s main Shiite political bloc and supporters of cleric Muqtada al-Sadr have signed a fragile cease-fire covering the Baghdad slum.

There has been sporadic fighting since the cease-fire went into effect Sunday.

Hospital officials say clashes erupted late Monday and intensified Tuesday. It was not immediately clear if the killed and wounded were militants or civilians.

The officials spoke on condition of anonymity because they were not allowed to talk to the media.

The U.S. military also reported Tuesday that a helicopter came under fire Saturday by a surface-to-air missile over Sadr City but escaped the attack.