Iraqi forces have declared northern Iraq clear of Islamic State after retaking the city of Hawija, one of the jihadist group’s last remaining strongholds in the country.

Announcing the liberation, Haider al-Abadi, Iraq’s prime minister, called it a "victory not just for Iraq but for the whole world."

Iraqi forces have driven Isil from nearly all the cities and towns it seized in the summer of 2014, including the country's second largest city, Mosul, which was liberated in July.

The extremists now control just a wedge of territory straddling the Iraq-Syria border and a cluster of towns further south in Anbar province.