Iraq's central government on Monday unleashed a legal barrage against Kurdish officials and sought to seize key businesses in a fresh bid to tighten the screws over a disputed independence referendum.

The latest moves come exactly two weeks after an overwhelming majority of voters in Iraq's autonomous Kurdistan region backed independence in a non-binding ballot slammed as illegal by Baghdad.

The central authorities have already severed ties between Kurdistan and the outside world by cutting international air links to the region, while neighbouring Turkey and Iran have threatened to close their borders to oil exports.

Now, in a new round of attempts to ratchet up pressure, Baghdad's National Security Council announced that a probe has been launched into Kurdistan's lucrative oil revenues and officials in the region who might have illegally monopolised the market.

"The corrupt will be exposed and the funds recovered," said a statement from the council, headed by Prime Minister Haider al-Abadi.

The council also said that "a list of names" of Kurdish officials who helped organised the referendum had been compiled and "judicial measures have been taken against them", without giving more details.

The central government -- which has already demanded to take over Kurdistan's airports and borders -- is also looking to reclaim control over mobile phone companies in the region, including two of the largest providers in Iraq, the statement said.

Baghdad also once again called on Ankara and Tehran -- which both opposed the referendum over fears of fuelling demands from their own Kurdish communities -- to close their border posts with Kurdistan and "stop all trade" with the region.

The angry dispute over the referendum -- also rejected by the US -- is the latest twist in the decades-long movement by Iraq's Kurds to break away from Baghdad.

The referendum spat comes as Kurdish fighters and central government forces have continued to work together in offensives to push back the Islamic State group, with Washington warning the poll could "increase instability" in the region.

The defence committee in Iraq's parliament demanded Kurdish security forces hand over IS fighters captured in a recent battle to retake the jihadist bastion of Hawija.

The US-led coalition backing up the operations against IS has estimated that some 1,000 jihadists surrendered, mostly to the Kurdish peshmerga forces, during the seizure of the town.

Source: AFP