Kurdish peshmerga fighters, shown here voting in last month's independence referendum, are on alert for a possible attack by Iraqi troops and allied militia

Kurdish authorities accused the Iraqi government on Friday of massing forces in readiness for an offensive to seize Kurdish-held oil fields, as tensions soar after a vote for independence last month.

The accusation came after Kurdish peshmerga fighters briefly closed main roads out of federal government-held areas on Thursday for fear of attack further north.

The Kurdistan Regional Security Council (KRSC) said that federal troops and allied paramilitary units had been massing in two areas south of Kirkuk, a Kurdish-held but ethnically divided city that lies at the heart of the decades-old dispute.

It said that both the army and Popular Mobilisation Forces (PMF) -- paramilitary units dominated by Iran-trained Shiite militia -- had been deploying tanks and heavy artillery to Bashir and Taza Khurmatu, two mainly Shiite Turkmen areas.

"These forces are approximately three kilometres (two miles) from peshmerga frontline positions," it said.

"Intelligence shows intention to take over nearby oil fields, airport and military base."

Kirkuk province is the location of northern Iraq's main oil fields and, even though far more crude is now pumped from the south, it is bitterly disputed between Baghdad and the Kurds.

Baghdad continues to reject decades-old Kurdish ambitions to incorporate the province and other areas, including districts north of second city Mosul, in their autonomous region.

On Thursday, Kurdish peshmerga closed the two main roads from Mosul to the Kurdish cities of Arbil and Dohuk for several hours for fear of an attack in the area, Kurdish officials said.

Iraqi Prime Minister Haider al-Abadi denied any attention of ordering an assault on his own people but the Kurds were unconvinced and accused the army's militia allies of trying to provoke a confrontation.

"We call on the Iraqi government to stop the PMF aggression in Kirkuk and north Mosul," the KRSC said.

"Kurdistan continues calling for dialogue and peaceful means to settle differences. The international community too must denounce the military deployments and call on the Iraqi government to return to talks."

The rise in tensions came two weeks after Kurdish voters overwhelmingly backed independence in a non-binding referendum that the federal government condemned as illegal.

Polling was held not only in the three provinces that have long formed an autonomous Kurdish region but also in neighbouring areas, including Kirkuk, that Kurdish forces seized from the Islamic State group during the fightback against the jihadists' lightning 2014 offensive through areas north and west of Baghdad.