BAGHDAD (Reuters) – Iraqi forces and Kurdish Peshmerga fighters reached an agreement on Friday to stop fighting in northern Iraq, the media office of the U.S.-led anti-Islamic State coalition said.

A spokesman for the coalition in Baghdad told Reuters the ceasefire agreement covered all fronts.

Iraqi government forces and the Iranian-backed Popular Mobilisation launched a surprise offensive on Oct. 16 in retaliation to a Sept. 25 referendum on independence organized by the Kurdistan Regional Government (KRG) in northern Iraq.

The offensive aims to capture so-called disputed territories, claimed by both the KRG and the Iraqi central government, as well as border crossings and key oil facilities.

The oil-rich city of Kirkuk fell to Iraqi forces without much resistance on Oct. 16 but the Peshmerga began to fight back forcefully as they withdrew closer to the core KRG territory.

The most violent clashes happened in the northwestern corner where Peshmerga are defending land crossings to Turkey and Syria and an oil hub that controls KRG crude exports.