The US military has started shelling the northern Iraqi city of Mosul in an offensive to retake the city from Islamic State (Isis), a Peshmerga commander has said.

Omer Huseyin, who is based in Camp Bashiqa 25km (15.5 miles) northeast of Musul, told Turkish-based Anadolu Agency that American howitzers have started hitting IS (Daesh) targets in the city.

The Daesh terrorists started burning tires to block the view of the warplanes after international coalition forces struck the area, he said. Daesh terrorists also started burning the petroleum filled in their ditches, which they have dug around the city.

However, US Central Command has denied that bombing of Mosul and said that Anadolu Agencys reporting was erroneous.

Brett McGurk,The US Special Presidential Envoy for the Global Coalition to Counter IS, said that the Mosul offensive will begin after Iraqs Prime Minister Haider Al-Abadi gives the go-ahead.

In a tweet, he said: Mosul operation will begin when announced by PM Abadi. Anything said before then is premature.

Despite the conflicting reports, if the offensive has not yet started, but it is imminent.

The Iraqi army dropped tens of thousands of leaflets over Mosul before dawn on Sunday (16 October), warning residents that preparation for an offensive was in its final stages.

Its victory time, said one of the leaflets. Time to celebrate a clean Iraq without Daesh or any dark belief.

Another leaflet said: We are preparing to take action to free Mosul and regain security and stability in the region.

Surrender of Mosul

Mosul fell to IS in early June 2014, after the rapid capitulation by the Iraqi military, whose members reportedly abandoned their posts as the Islamist militants advanced.

The offensive to recapture the city will be a joint operation by the Iraqi military, Kurdish Peshmerga and a Shiite paramilitary force.

IS fighters are dug in and are expected to fight hard, Reuters reported. They have forced civilians to stay in harms way during previous battles to defend territory.

The United Nations Office for the Coordination of Humanitarian Affairs in Iraq has said the fallout from the offensive could be one of the worlds biggest humanitarian disasters.

It estimated that upwards of 1.2m people will be affected and that over 700,000 will need emergency accommodation.