Attacks in Baghdad and the main northern city of Mosul on Thursday killed five people as an Al-Qaeda front group claimed an assault on a mall and adjoining police complex.

The violence was the latest in a protracted surge in bloodshed that has killed more than 6,200 people already this year, forcing the authorities to appeal for international help just months ahead of elections.

Officials have blamed a resurgent Al-Qaeda emboldened by the civil war in neighbouring Syria, but the government has itself been criticised for not doing enough to address the concerns of the disaffected Sunni Arab minority.

Shootings and bombings in the capital and Mosul, a restive predominantly Sunni city in north Iraq, killed five people, security and medical officials said, while security forces found the bodies of two anti-Al-Qaeda militiamen.

The militiamen were members of the Sahwa, a collection of Sunni tribal militias that sided with the US military against their co-religionists in Al-Qaeda from 2006 onwards.

As a result, Sunni militants regard them as traitors and often target them.

The bloodshed came as the Islamic State of Iraq and the Levant (ISIL) claimed it was behind a massive coordinated attack on a shopping mall and adjoining police intelligence office in the northern tinderbox city of Kirkuk.

Overall, the attack -- which involved a car bomb, a firefight and several would-be suicide bombers -- killed 11 people and wounded 79, according to officials. Five militants were also killed.

"Thanks to God, they (ISIL fighters) carried out the order to invade the house of the unbelievers by raiding the headquarters of the intelligence in Kirkuk," a statement posted on a jihadist forum said.

Kirkuk has a mixed population of Arabs, Kurds and Turkmen.

It lies at the centre of a swathe of territory stretching from Iraq's eastern border with Iran to its western frontier with Syria that Kurdish leaders want to incorporate into their autonomous region in the north over strenuous objections from the central government in Baghdad.

Militants often exploit poor communication between the Iraqi army and Kurdish security forces to launch attacks in the city.

Violence has spiked this year after security forces stormed a Sunni protest camp north of Baghdad in April, amid months of demonstrations by Iraq's Sunni Arab minority which complains of discrimination at the hands of the Shiite-led authorities.

The government has made some concessions aimed at placating Sunni Arabs, including freeing prisoners and raising the salaries of anti-Al-Qaeda fighters, and have also trumpeted security operations against militants.

But daily attacks have shown no sign of abating.

Despite a near-ubiquitous security force presence, attacks have hit targets ranging from cafes and football grounds to military checkpoints and government vehicles.