'Disguised' IS gunmen storm football fan club, kill 16 north of Baghdad

Gunmen attacked a Real Madrid supporters club in Baghdad, killing at least 16 people in the club and during the subsequent manhunt, Iraqi officials said on Friday.

The Islamic State group attackers stormed the cafe north of Baghdad, opened fire and threw grenades into the crowd. As the police started to pursue the attackers, they detonated suicide belts, authorities said.

Up to 30 additional people, including several members of the security forces, were wounded in the attack and the ensuing chase in the town of Balad.

Gruesome scenes have since started to filter through on social media, showing bloodied walls and floors in the cafe.

Officials said the gunmen were from the Islamic State group, which claimed the attack in an online statement.

The attack is the latest in a string to hit Baghdad and surrounding areas where more than 115 people have now been killed in 36 hours. 

"A group of armed men from Daesh [an Arabic acronym for IS] disguised in security force uniforms attacked a cafe in Balad at around midnight, using grenades and gunfire," Ammar Hekmat al-Baldawi, a deputy governor of Salaheddin province, told the AFP news agency.

"They fled to a nearby farming area. They blew themselves up when the security forces and some residents chased them and got close," he said.

"There were five or six attackers - four of them blew themselves up. The hunt is not over because we think there could be up to two of them still on the run," he said.

The Real Madrid club, as well as a host of fans, took to social media to express their solidarity with Iraq and those killed. 

Several members of the police and the Hashd al-Shaabi paramilitary organisation, mainly made up of Shia militiamen, were among the dead.

The style of the attack was a departure from the suicide car bombings IS has used as its main tactic to inflict maximum casualties in Shia-dominated towns and cities of Iraq.

Balad is a large town 80 kilometres north of the Iraqi capital.

A police lieutenant colonel who declined to give his name said the shooting claimed 12 lives, and that four other people, two police and two members of Hashd forces, were killed later when one attacker detonated his suicide belt.

A doctor at a local hospital in Balad gave the same toll.

In its statement posted on social media, IS said a unit of three militants had stormed a gathering of Hashd members (Shia militia members) shooting several dead, before one of them blew himself up as rescue services tried to evacuate the wounded.

It said the two other attackers killed several other people when they detonated their explosive belts.

The organisation said the attack was the latest in a campaign to honour Abdel Rahman Mustafa al-Qaduli, the group's second-in-command, who was killed in a coalition strike in March.

IS has been steadily losing ground to Iraqi forces on the battlefield lately but has upped its campaign of bombings against civilians.

At least 94 people were killed in three suicide attacks in Baghdad on Wednesday, the deadliest day in the Iraqi capital this year.

Meanwhile, Islamic State snipers are targeting humanitarian corridors established by Iraqi security forces to relieve suffering in the IS-held city of Fallujah, a Pentagon official said on Friday.

Baghdad-based military spokesman Colonel Steve Warren said the shooters were preventing residents from escaping Fallujah, which is only about 50km west of Baghdad and is facing major shortages of basic supplies including medicine.

"We know that the Iraqis have attempted on several occasions to open up humanitarian corridors to allow some of those civilians to come out," Warren told Pentagon reporters in a video call.

"Those have met with generally not much success. ISIL has done things like set up snipers to cover down on those corridors, to kill people as they're trying to get out. So that has really discouraged their use," he added, using an acronym for the IS group.