Iraq's armed forces have started an attack to dislodge the Islamic State of Iraq and the Levant (ISIL) group from the key centre of the city of Ramadi, sources told Al Jazeera.

The attack on the capital of Anbar province began on Tuesday morning, Sabah al-Numani, spokesman for the army's counterterrorism units, told the Reuters news agency.

On Monday, army chief of staff General Othman al-Ghanemi told state television that Iraq's armed forces would start the operation "very soon".

"There is an ongoing operation to control a sector in preparation of the onslaught on the city centre within the coming hours, God willing," he said.

An Iraqi defence ministry spokesman said earlier that ISIL was preventing civilians from leaving Ramadi before the planned attack on the city, which fell under control of the group in May.

Iraqi military planes on Sunday dropped leaflets on Ramadi, asking residents to leave within 72 hours and indicating safe routes for their exit.

Iraqi intelligence estimates the number of ISIL fighters who are entrenched in the centre of Ramadi, capital of Anbar province, at between 250 and 300.

Courtesy Aljazeera