Baghdad  - Iraqi police on Tuesday arrested the suspected perpetrators of a restaurant bomb attack in Kirkuk that left 45 dead and 85 injured, including many women and children.

The attack earlier this month in a restaurant during the Muslim feast of sacrifice, Eid al-Adha, was the work of a suicide bomber, police said at the time.

Kurdish security forces, with the help of US forces, arrested members of an Islamist extremist group that claimed responsibility for the attack. Police also confiscated 250 kilograms of TNT and bombs.

Kirkuk is a multi-ethnic city with a population of Kurds, Arabs and Turkmans located near Iraq's semi-autonomous Kurdish region.

A security source in Kirkuk denied the involvement of Kurds or Turkmans in the attack. Rumors of Kurdish and Turkman involvement harmed relations between the groups, the source said.

Meanwhile, a bomb exploded killing a child and injuring six civilians on Tuesday in the northern city of Mosul, a police source told Deutsche Presse-Agentur, dpa.

Also in Mosul, unidentified gunmen in a car shot and killed a doctor on his way to work.

Five Iraqi policemen were killed in a blast that ripped through their patrol vehicle in northern Baghdad, according to a security source.

"An improvised explosive device planted by unknown gunmen on the main road in Baghdad's northern area of al-Mushahada detonated while the motorcade of a local police chief was passing by, killing him along with four of his security guards," the source was quoted by the Voices of Iraq news agency as saying.

Violence has significantly decreased in most of the Iraqi provinces except for Baghdad and Mosul. Pacifying the two provinces remains a challenge for the US and Iraqi forces. (dpa)