Anbar tribal forces have started conducting pre-emptive attacks deep into "Islamic State of Iraq and Syria" (ISIS) territory in western parts of the province to pave the way for a military offensive to expel the group from the area.

They are conducting "quality, close-range attacks deep into ISIS-held positions in the cities of Anah and Rawa", Haditha tribal mobilisation commander Awad al-Jughaifi told Diyaruna on Wednesday (August 16th).

"A storm unit comprised of Albu Mahl tribesmen carried out the first of those attacks when it pushed into militant strongholds," he said.

The unit reached a junction on the road leading to Anah and Rawa, only a few kilometres from the centre of the two cities, he said.

"The fighters clashed violently with ISIS elements holed up in the area and bombed their barracks with mortars, killing 11 terrorists and disabling two vehicles," al-Jughaifi said.

One tribal fighter died and four others were wounded, he said, adding that the tribal unit returned to its base after successfully completing its operation.

Prelude to military campaign

"There will be at least one operation of this type every week," he said. "These pre-emptive attacks will pave the way for a major military campaign to eliminate ISIS in western Anbar."

"We continue our preparations for the campaign and we will provide the required support to the security forces during the fighting, and take part in holding liberated territory," al-Jughaifi said.

ISIS is currently besieging at least 4,000 families in the city of al-Qaim after many locals have escaped, he said, stressing that the objective is to rescue all residents and to end the group's presence in the province.

Thousands of civilians in recent months have managed to escape ISIS-held territory and reach al-Rutba using hidden roads through the desert.

ISIS elements, numbering about 1,500, remain in control of three cities in western Anbar: Anah, Rawa, and al-Qaim -- which they use as launching pads for attacks on the cities of Haditha and al-Rutba.