The so-called Islamic State of Iraq and Levant (ISIL) extremist group has executed 20 soldiers in Fallujah in Iraq’s western Anbar province

The so-called Islamic State of Iraq and Levant (ISIL) extremist group has executed 20 soldiers in Fallujah in Iraq's western Anbar province, a local tribal source said Monday.

"The soldiers were executed after being held hostage following an attack by tribesmen on an Iraqi army garrison," the source, who spoke on condition of anonymity, told Anadolu Agency.

Tribesmen, he said, had attacked an army garrison in southern Fallujah, triggering a five-hour confrontation with army personnel. Tribesmen managed to capture 20 soldiers, torch three military vehicles and establish control over the garrison.

He noted that two tribesmen had been killed and a third seriously wounded in the confrontation.

"The tribesmen took the soldiers to Fallujah, where the ISIL took them and executed them last Saturday – less than 24 hours after receiving them," the tribesman said.

The group executed four other soldiers two weeks ago after capturing them in eastern Ramadi.

The Iraqi army has been waging a major military operation in the restive Anbar province since last December with the stated aim of flushing out Al-Qaeda-allied extremist fighters.