Attackers armed with suicide vests, rifles and grenades killed 18 people in the Iraqi oasis town of Ain al-Tamer, many of them guests at a wedding party, local officials said Monday.
"They were carrying Kalashnikovs, hand grenades. One of them blew himself up and the others were killed by the security forces," said the head of central Euphrates operations command, Qais Khalaf.
A local council member and a provincial health directorate source confirmed the death toll in the attack, which took place late Sunday, and said at least 26 others were wounded.
There was no immediate claim of responsibility but all recent suicide operations in Iraq have been claimed by the Islamic State (IS) jihadist group.
Ain al-Tamer, southwest of Baghdad, is located 50 kilometres (30 miles) from the Shiite holy city of Karbala and on the edge of Anbar province, long a haven for jihadists.
Officials said the attackers started opening fire in a neighbourhood of Ain al-Tamer at around 1830 GMT on Sunday, although it was not immediately what their target was.
Five members of the same family were among the dead, according to a health official from Karbala province.
"The five terrorists were carrying lots of weapons and one of them blew himself up in the midst of our citizens," said Farhan Jassem Mohammed of the local council.
"Some of them were wearing civilian clothes, others military clothes. They infiltrated from the west under the cover of darkness," he said.
"One of them may have managed to flee. There is an ongoing search," Mohammed told AFP.
A former mayor of Ain al-Tamer told AFP the attackers started spraying bullets at a nearby wedding party.
"The attack kicked off as people were attending a wedding party in the neighbourhood. Several among the dead and wounded were at the party," said Mahfouz al-Tamimi, who is now a Karbala provincial council member.
Military commanders said the attackers came from the Anbar desert to the west, a region that is overwhelmingly Sunni and borders Saudi Arabia, Jordan and Syria.
Iraq\’s security forces have for months been battling IS fighters in Anbar, notching up key victories in provincial Ramadi and jihadist bastion Fallujah earlier this year.
IS recently lost control of an area in Anbar called Jazirat al-Khaldiyeh, a key crossroads that jihadists used to move fighters and supplies between fronts since they seized large parts of Iraq in 2014.
The attack on Ain al-Tamer, in which guerrilla fighters doubled up as suicide bombers, bore the hallmark of IS.
The jihadists call such operations "inghamasi" — which literally means "plunging" and refers to the act of penetrating deep into enemy territory.