BAGHDAD: Militants linked to the Islamic State group have rounded up dozens of men from two villages in northern Iraq following a quarrel that led to the burning of the extremist group’s flag, tribal leaders said on Saturday.

The latest move by the extremist militants came as the UN said that last year saw the highest causality figures in Iraq in over five years.

Two sheikhs said the militants entered a mosque in the village of Al-Shajara on Friday as worshippers gathered for prayers, removing flags commemorating the birth of Prophet Muhammad (peace be upon him)and hoisting their own black Islamic State group flag.

That prompted a verbal quarrel between the militants and the worshippers, who later burned the Islamic State group flag. The militants then snatched up around 140 men from their homes in Al-Shajara and from the nearby village of Al-Ghariba village, both around 70 kilometers outside the northern city of Kirkuk.

Around 100 of the men were later released, while the rest remained in captivity, the sheiks said on condition of anonymity, fearing for their own safety.

The IS group controls around a third of both Iraq and neighboring Syria, where it has declared an Islamic caliphate and imposed a violent form of Shariah law.

In its monthly release issued on Friday, the UN Assistance Mission in Iraq said a total of 12,282 Iraqis were killed and another 23,126 injured in violence in 2014, making it the bloodiest year since 2006-2007.

The violence has spiked as the Islamic State group’s advances have sparked renewed sectarian tensions between Sunnis and Shiites. The latest incident took place Thursday in the mostly Shiite southern city of Basra, where gunmen shot dead three Sunni clerics.