An Iraqi court on Wednesday ordered the arrest of senior Kurdish officials responsible for organising an independence referendum, in the latest salvo by the central authorities over the disputed vote.

The decision ratchets up pressure on Iraqi Kurdistan just over two weeks after voters in the autonomous region overwhelmingly backed independence in the non-binding ballot slammed as illegal by Baghdad.

Acting on a request from the National Security Council headed by Iraq's prime minister, a court in east Baghdad issued warrants against the chairman of the vote's organising commission Hendren Saleh and two other members, Supreme Judicial Council spokesman Abdel Sattar Bayraqdar told AFP.

It ruled that the three "organised the referendum in contravention of a ruling by the Iraqi supreme court," which had found the vote unconstitutional and ordered it called off.

The supreme court ruling came one week before the September 25 referendum, but the organisers went ahead with it regardless.

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

- 'Political decision' -

The court's arrest order is likely to prove toothless as Baghdad's security forces do not operate inside Kurdistan, but it could stop the officials leaving the region.

Vote commission chief Saleh shrugged off the ruling as of "no importance", insisting that it was a purely "political decision".

Even if it does prove symbolic, the move still represents the latest step in a broader onslaught designed to tighten the legal and financial screws on Arbil.

The National Security Council on Monday said "a list of names" of Kurdish officials who helped organised the referendum had been compiled and "judicial measures have been taken against them".

Iraq has also launched a probe into Kurdistan's lucrative oil revenues and pledged to expose "corrupt" officials in the region who might have illegally monopolised the market.

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

The authorities also announced Tuesday that they are looking to reopen a key oil pipeline to Turkey that would rival a competing Kurdish export route.

The Iraqi pipeline was cut off after the Islamic State group seized swathes of the country in 2014, halting a flow of oil to Turkey of up to 400,000 barrels a day.

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

Iraq is pushing Turkey and Iran -- which both opposed the ballot over fears of fuelling demands from their own sizeable Kurdish communities -- to close their border posts with Kurdistan and stop all trade with the region.

Washington warned the referendum could "increase instability" in the region and have an impact on the battle against IS, in which Kurdish fighters have been a key force.

source: AFP