Kurdish media says Iraq's autonomous Kurdish region has sent 6,000 reinforcements to the disputed, oil-rich city of Kirkuk.

Rudaw News, quoting Kurdish Vice President Korsat Rasul, says the reinforcements were sent to Kirkuk late Thursday in response to what it says are threats from Baghdad to attack the oil-rich city, which is controlled by Kurdish forces but outside the autonomous Kurdish region.

The Kurds took control of Kirkuk when the Islamic State group swept across northern Iraq in 2014 as the Iraqi military crumbled. Baghdad has demanded the Kurds return to the city to federal authorities, a dispute that has escalated since the Kurds voted for independence in a non-binding referendum last month.

Iraq's Prime Minister Haider al-Abadi has ruled out the use of military force against the Kurds.