Five suspected Al Qaeda members were arrested Tuesday in the northern Iraqi city of Mosul, a police source said.

'Three of the suspects admitted to firing mortar shells on several polling stations in the city Sunday,' the source said, adding that the suspects were arrested in the Tel al-Ruman area of western Mosul.

Five polling stations were closed Sunday after mortar rounds landed on one of them, leaving six observers injured. Separate attacks across the city left at least 25 people injured.

A wave of attacks across Iraq targeting voters left dozens dead and more than a hundred injured.

Some 18.9 million Iraqis were eligible to vote in Sunday's polls, Iraq's second since the 2003 US-led invasion of the country.

The source added that a decapitated body of a woman in the same area was found and handed over to the forensic department in the city.