Gunmen from the ISIL terrorist group attacked an army barracks in a mountainous area north of Baghdad early Friday, killing 11 soldiers as they slept, Iraqi security officials said.

The officials said the attack occurred in the Al-Azim district, an open area north of of Baqouba in Diyala province. The circumstances of the attack were not immediately clear, but two officials who spoke to The Associated Press said  ISIL group militants broke into the barracks at 3 a.m. local time and shot dead the soldiers.

The officials spoke on condition of anonymity as they weren’t authorized to issue official statements.

The brazen attack more than 120 kilometers north of the capital Baghdad was one of the deadliest targeting the Iraqi military in recent months.

ISIL terrorist group was largely defeated in the country in 2017, although it remains active through sleeper cells in many areas. Militants from the  extremist group still carry out operations, often targeting security forces, power stations and other infrastructure.