An attacker detonated explosives hidden inside a vehicle at the entrance to the stadium in Tal Afar, a mainly Shia Turkmen town west of Mosul.

Witnesses said the blast was followed by at least one other. Some said up to three suicide bombers were involved.

No group has yet claimed responsibility for the bombings, but correspondents say the method was similar to past al-Qaeda attacks and the group remains active in the area.

Many people were gathered to watch the match, said Hussein Nashad, who attended the game.

"We heard a loud explosion and the people behind me shielded me from the shrapnel. I ran away, but then I heard someone shout 'Allahu Akbar', and then there was another explosion," he said.

On May 10, more than 100 people were killed in a series of apparently co-ordinated attacks blamed on al-Qaeda and its allies.