The spokesman of Iraq's state-sanctioned paramilitaries has issued a stern warning to Masoud Barzani while saying his fighters have no immediate plans to take military action against the Kurdish leader.

Karim al-Nouri, spokesman for the Popular Mobilisation Forces (PMF), has accused the president of the Kurdistan Regional Government (KRG) of behaving like the leader of a "fifth column" during the war against ISIL, or the Islamic State of Iraq and the Levant group.

The PMF consists of mainly Shia Arab paramilitaries, many of which are backed by neighbouring Iran.

Barzani "is more dangerous than Daesh because he comes from within Iraq," said Nouri, using the Arabic term for ISIL, also known as ISIS.

The referendum of September 25 organised by Barzani, in which more than 90 percent voted for secession, escalated long-running tensions between the Iraqi Kurdish region and the central government over the sharing of oil wealth and the fate of disputed territories such as Kirkuk.

Kirkuk is held by Kurdish forces, but lies outside their semi-autonomous zone.

Iraq, Iran and neighbouring Turkey have all rejected the referendum and insist Iraq's borders will not be redrawn.

Summer of 2014

Nouri accused Kurdish forces, known as the peshmerga, of "occupying" Kirkuk and "stealing the oil wells".

The peshmerga assumed control of the oil-rich, multi-ethnic Kirkuk in the summer of 2014, when ISIL swept across northern Iraq and the Iraqi military crumbled.

"Anyone occupying Iraqi land must be thrown out. We do not discriminate between Daesh and anyone else in this manner," Nouri told the Associated Press news agency.

He said the paramilitaries have no immediate plans to move on the city, and would follow orders from Baghdad. But other commanders suggested clashes were on the horizon.

"I think Kirkuk will stay Iraqi, and there will be a major sacrifice to retake Kirkuk, after the approval of the Iraqi government," said Rayan al-Kaldani, commander of the Babylon Movement, a Christian militia in the PMF.

Haider al-Abadi, Iraq's prime minister, has ruled out military action in response to the referendum, but has also said he will deploy Iraqi forces in response to any violence.

Iraqi Vice President Iyad Allawi said on Monday there could be "civil war" over Kirkuk if the two sides failed to show restraint.

Reports of 'major attack'

On Wednesday, the Kurdish authorities accused Iraqi government forces and the Shia Arab paramilitaries of "preparing a major attack" on Kirkuk and the area near Mosul.

The peshmerga closed roads to Kirkuk early on Thursday after Kurdish authorities warned that the Iraqi government was moving forces in the direction of the city. They reopened them later in the day.

A leading official of a Kurdish opposition party offered late on Thursday to dissolve the Kurdish administration of Kirkuk and enter into "unconditional negotiations" with Baghdad over the city.

Kirkuk's governor belongs to the party known as the PUK.

Befal Talabani, son of Jalal Talabani, the late Iraqi president, said he wanted to avoid war with the Iraqi central government.

Talabani's PUK is a rival of Barzani's KDP party and enjoys good relations with Iran.

The Iraqi government said on Thursday it would not hold talks with the KRG on reopening its airports and providing dollars for its banks, unless the Kurds commit to "Iraq's unity".

Punitive measures

Iraq's central government imposed a ban on direct international flights to the land-locked region, stopped selling dollars to four Kurdish-owned banks and called for a halt to its independent crude oil sales.

The Kurds have repeatedly called for negotiations following the referendum in which an overwhelming majority voted for independence.

"To avoid this collective punishment, we invite Haider al-Abadi, again, ... [to] any form of dialogue and negotiations in conformity with the Iraqi constitution," the KRG said in a statement.

It offered discussions "regarding the crossings, internal trade, providing services to the citizens, the banks and the airports".

The US, long friendly with the Kurds, had also called on them before the referendum to cancel it.

Turkish President Recep Tayyip Erdogan's spokesman said on Thursday his country would gradually close border crossings with northern Iraq in coordination with the central Iraqi government and Iran.