"Armed men on motorbikes" abducted the group on Sunday as they collected truffles in the Al-Nukhaib region in the desert between Najaf and Al-Anbar provinces, security forces said in a statement Monday evening.

The governor of Al-Hira district in southern Najaf province, Abdul Wahed al-Fatlawi, told AFP on Tuesday that "the bodies of six people from the same clan" had been found.

They had been shot dead.

He said the bodies had been taken to a forensic lab in Karbala province, and accused the Islamic State group of carrying out the murders.

Iraq declared victory over the jihadist organisation in late 2017 following a punishing campaign to dismantle its self-declared "caliphate" covering a third of the country.

But IS militants have continued to carry out bombings, abductions and killings.