PLEASE NOTE: EDIT CONTAINS MATERIAL THAT WAS ORIGINALLY 4:3<br/> <br />Two bombs went off at this Sunni mosque near the Iraqi city of Samarra during Friday prayers.<br/> <br />The devices were hidden in an air conditioning unit.<br/> <br />At least 15 people have been killed.<br/> <br />At least 17 more have been wounded.<br/> <br />It wasn't immediately clear who was behind the attack.<br/> <br />But Iraq's delicate sectarian balance is under growing strain from the civil war in neighbouring Syria.<br/> <br />Both Sunni and Shi'ite Muslims have crossed into Syria from Iraq to join the conflict on both sides.<br/> <br />Syria's rebels are mainly Sunnis fighting to oust a president backed by Shi'ite Iran.
