IRAQI forces launched their long-awaited offensive to capture the Islamic State (Isis) stronghold of Mosul yesterday, gaining ground within hours.

Prime Minister Haider al-Abadi announced the start of the big push in a televised address late on Sunday night.

Local Sunni Muslim and Assyrian volunteers, Shi’ite-dominated Popular Mobilisation Units and Kurdish Peshmerga forces joined the army in driving out the death cult from the capital of Nineveh province on the Syrian and Turkish borders.

Some 25,000 troops advanced under cover of heavy artillery barrages, taking the once multiethnic city of Bashiqa to the north-east of Mosul before dawn.

Kurdish regional government president Masoud Barzani tweeted: “The time has come to begin the liberation of Mosul,” as his forces took 80 square miles and six villages on the first day.

Mr Barzani’s Kurdistan Democratic Party is opposed by the Kurdistan Workers Party which is allied to the US-backed YPG militia fighting Isis in northern Syria.

Isis said it had retaliated with suicide car bomb attacks on the government forces.

Turkish President Recep Tayyip Erdogan insisted that his country, which has kept troops stationed north of the city despite Iraqi orders for them to leave, should play a part in the offensive and talks on the city’s future.

He said that, after Mosul’s liberation, Turkey would not allow “Sunni-Shi’ite strife” in the city, reiterating sectarian comments that sparked a diplomatic row last week.

Turkish Deputy Prime Minister Numan Kurtulmus said some 3,000 of the 4,000 local militia members trained by the Turks were already involved in the fighting.

But, as a key backer of fundamentalist guerillas — and allegedly Isis itself — in neighbouring Syria, Turkey has little credibility as an interlocutor.

In Damascus, the Foreign Ministry welcomed the offensive, saying: “Victory over Isis in Iraq is a victory over Isis in Syria.”

It said the battle was not only against terrorism but also against “those who support, arm and fund it” — a thinly veiled reference to Western and Gulf Arab states as well as neighbouring Turkey.

It warned of Ankara’s “dangerous and aggressive” opposition to the participation of Shi’ite militias in Mosul’s liberation, saying those who oppose or obstruct the fight against extremists were backing terrorism.

The United Nations and international aid groups voiced fears that up to a million people — equal to the entire pre-war population of the city and its environs — could be displaced by the offensive.