The attack occurred at night in the Makhmur region south of Mosul, the former stronghold of the IS jihadists, a security official said on condition of anonymity.

It left dead four people, including the mayor of the hamlet, at least one police officer and a member of the pro-Iran Hashed al-Shaabi militia, the official added.

Jihadists from "Daesh" had targeted a Hashed position at around 2:00 am (2300 GMT), Salih al-Jiburi, an official from a nearby village, said, using the Arabic acronym for IS.

They shelled and fired small arms during the attack, said Jiburi, who put the toll at four dead, including the mayor and militia fighter.

The attack comes less than a week after an IS assault near the northern city of Kirkuk killed 13 members of the Iraqi federal police.

The jihadists also claimed responsibility for a major attack in July that killed more than 30 people at a market in Baghdad's Shiite district of Sadr City.

IS overran Mosul in a lightning offensive in 2014, and for three years the mainly Sunni city was the heart of the jihadists' self-proclaimed "caliphate".

The city was retaken by the Iraqi army and a US-led coalition after intense bombardment and fighting that left it in ruins.

International coalition troops in Iraq currently number around 3,500, of which 2,500 are US troops.