Iraqi and Kurdish forces exchanged fire over their shared border on Friday in the most serious clashes since the crisis began, as federal forces ousted the Kurds from remaining disputed territory.

Iraq's anti-terrorism and federal police forces shelled Kurdish Peshmerga military positions in Altun Kupri, just outside the country's autonomous Kurdish region.

The Peshmerga responded with mortar fire. There were no reported injuries.

The Kurdistan Regional Security Council claimed that weapons supplied by the US to the Iraqi army was being used in the attack against them.