Gunmen and suicide car bombers on Thursday killed at least 52 people including Iranians near the southern Iraqi city of Nasiriyah, in an attack claimed by terror group ISIS.

The attackers struck at midday, opening fire on a restaurant before getting into a car and blowing themselves up at a nearby security checkpoint, officials said.

Security sources said the attackers were disguised as members of the Hashed al-Shaabi.

The toll from the attacks was 52 dead and 91 wounded, said Abdel Hussein al-Jabri, deputy health chief for the Dhiqar province of which Nasiriyah is the capital.

Jabri told AFP that many of the wounded were in serious condition.

ISIS claimed responsibility for the attacks in a statement carried by its Amaq propaganda arm.

It said several suicide bombers had staged the assault on a restaurant and a security checkpoint.

The toll makes it the deadliest ISIS attack in Iraq since pro-government forces drove the extreists out of second city Mosul in July.

The Sunni extremist group regularly stages attacks in Iraq, where it has also lost swathes of territory to US-backed pro-government forces.

Thursday’s attacks come as Iraqi forces backed by tribal fighters close in one of the last ISIS bastions in the country: the Al-Qaim area on the border with war-ravaged Syria.

The group’s only other stronghold is Hawija, in Kirkuk province some 300 kilometres (185 miles) north of Baghdad.

ISIS has suffered a string of defeats on the battlefields of Iraq and Syria, leaving in tatters the cross-border “caliphate” it declared in 2014.

But any military offensive in Hawija is expected to be postponed due to a planned referendum on Kurdish independence.