Kurdish peshmerga forces have started clearing parts of the northern Iraqi town of Sinjar and have established positions along an Islamic State supply route between its two main strongholds in Iraq and Syria, the coalition said yesterday.

Backed by US-led coalition air strikes, the Kurds launched an offensive in the early morning designed to cordon off Sinjar, take control of strategic routes and establish a buffer zone to protect the town from artillery.

A victory in Sinjar could give the Kurds, government forces and Shi’ite militias momentum in efforts to defeat Islamic State, which controls large areas of Iraq and Syria and has affiliates in Libya and Egypt.

So far the Kurds have captured three villages and penetrated parts of Highway 47, a supply route between Raqqa in Syria and the Iraqi city of Mosul, both of them Islamic State bastions.

“The ground assault began in the early morning hours of November 12, when peshmerga units successfully established blocking positions along Highway 47 and began clearing Sinjar,” said the coalition in a statement.

Islamic State overran Sinjar over a year ago, killing and enslaving thousands

“The peshmerga will continue operations to re-establish government control over key portions of the areas.”

Islamic State, a hardline Sunni group, overran Sinjar more than a year ago.

Islamic State’s killing and enslaving of thousands of the northern town’s Yazidi residents focused inter­national attention on the group’s violent campaign to impose its radical ideology and prompted Washington to launch its air offensive. The US expectation is that it would take two to four days to secure Sinjar and another week to finalise clearing operations, a US military official said, speaking on condition of anonymity.

Members of the Kurdish peshmerga forces gathered in the town of Sinjar, Iraq, yesterday.

US military advisers are with Kurdish commanders near Sinjar mountain but are positioned well back from the fighting, a US military spokesman said.

US Army Colonel Steve Warren said some US advisers were also on Sinjar mountain working with the Kurdish peshmerga forces to advise and assist with the development of targets for air strikes.

The US military estimated that 60 to 70 Islamic State fighters had been killed in US-led coalition air strikes yesterday, said Col Warren, a Baghdad-based spokesman for the US-led coalition effort against Islamic State.

Islamic State uses Highway 47 to transport weapons, fighters and illicit commodities to fund its operations, said the coalition.