About 100,000 Kurds have fled the Kirkuk region fearing persecution since Iraqi armed forces retook it following a referendum on Kurdish independence that was rejected by Baghdad, according to Kurdish officials.

In a rapid advance on Monday and Tuesday, central government troops and allied militias swept into Kirkuk, a multi-ethnic city of more than one million people and the hub of a major oil-producing area, largely unopposed after Kurdish Peshmerga forces withdrew.

The advancing units also ousted Peshmerga fighters from formerly Kurdish-held areas of Nineveh and Diyala provinces.

Nawzad Hadi, governor of Erbil, the capital of the Kurdistan Regional Government (KRG), told reporters on Thursday that around 18,000 families from Kirkuk and the town of Tuz Khurmatu to the southeast had taken refuge in Erbil and Sulaimaniya, inside KRG territory.

A Hadi aide told Reuters news agency the total number of displaced people was about 100,000. The figure could not be independently verified, and many Kurdish neighbourhhoods in Kirkuk city appeared to be operating normally, Reuters reported.

Hemin Hawrami, a senior assistant to KRG President Masoud Barzani, said in a post on Twitter that 57,000 families from Kirkuk were in need of “immediate assistance” after arriving to Erbil, Sulaimaniya and Duhok provinces.

He said that people had fled “violence, looting and crimes” inflicted by the Popular Mobilisation Force (PMF), paramilitary units largely made up of Iran-trained Shia militias.

Due to atrocities Violence, looting, & crimes by PMF Since October 16th, 57,000 families fled from Kirkuk to Erbil ,Slemani & Duhok provencies due to by High number, they are settled in unfinished buildings & in public places. They need immediate assistance.

— Hemin Hawrami (@heminhawrami) October 19, 2017

A mayor from the town of Khanaqin, Mohammed Mulla Hassan, said a Kurdish man was killed and six wounded by Iraqi security forces while protesting at the army’s takeover there.

Kurdish troops had left Khanaqin, near the border with Iran, on Tuesday to avoid clashing with advancing Iraqi forces.

UN concern

Separately, the United Nations voiced concern at reports that civilians, mainly Kurds, were being driven out of parts of northern Iraq retaken by Iraqi forces and their houses and businesses looted and destroyed.

UN relief officials said they had received allegations that 150 houses had been burned and 11 blown up in Tuz Khurmatu and offices of Turkmen political parties in Kirkuk assaulted.

The UN Assistance Mission for Iraq issued a statement urging the Baghdad government “to take every action to halt any violations and ensure all civilians are protected and that the perpetrators of acts of violence, intimidation and forced displacement of civilians be brought to justice”.

Iraq’s Prime Minister Haider al-Abadi ordered all armed groups out of Kirkuk, with only the Iraqi army and federal police remaining. He insisted Kirkuk is safe and called for the protection of civilians.

However, many of those who fled Kirkuk said they would not return.

“People are saying Kirkuk is safe, but it is propaganda,” Karwan Rashid Mohammed, who was a policeman in the city until he fled on Tuesday, told Al Jazeera from an abandoned housing project on the outskirts of Erbil.

“At night, they come out and beat the youth. They have burned houses. That’s why we got scared – because of our families, that’s why we left,” he added.

Hinting at the internal divisions among the two main kurdish political parties – the ruling Kurdistan Democratic Party accused the Patriotic Union of Kurdistan of colluding with Iraqi government leaders, Iran and Turkey in orchestrating the takeover of Kirkuk.

“A political party sold us out. Not all Kurds are refugees, this is all political,” said Mohammed.

Nearby, Fauziah Hakim Ahmad, a 67-year-old black-clad woman sits on a thin blanket on a dusty floor.

“A lot happened to us – we don’t own our own house now, we don’t know if we have a house or our things,” she told Al Jazeera, recalling a lifetime of plight.

“Since I was a child, I’ve never seen happiness. It’s war after war,” she said. “Now they came to our homes and burnedthings- where should we go now?”;

Kurds comprise the largest community in Kirkuk, followed by Turkmen, Arabs and Christians, according to the Iraqi Planning Ministry.

In another sign of rising tensions, Iraq’s Supreme Justice Council ordered the arrest of KRG Vice President Kosrat Rasul for allegedly saying Iraqi troops were “occupying forces” in Kirkuk.

Iraqi Kurds say open to talks

Kurdish Peshmerga forces took control of oil-rich Kirkuk after the Iraqi army fled from a major offensive by the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group in 2014.

Since then, there had not been an agreement between the KRG and the federal government in Baghdad about who should control the area – and benefit from its vast oil wealth.

Neighbouring Iran and Turkey had joined Baghdad in condemning the September 25 referendum, in which Iraqi Kurds overwhelmingly voted for secession, worried it could worsen regional instability and conflict by spurring their own Kurdish populations to push for homelands. The United States had also opposed the vote.

With the referendum having given Abadi a political opening to regain disputed territory and tilt the balance of power in his favour, the KRG cabinet on Thursday welcomed his call for talks to resolve the crisis.

Abadi had said on Tuesday he considered the referendum “a thing of the past”, and asked that the KRG cancel the outcome of the vote as a precondition for negotiations to begin.

In a statement on Thursday, the KRG cabinet said, “It will not be possible to resolve the issues through military operations”.

It added: “(We have) asked the international community to help both sides start a dialogue to solve the outstanding issues based on the Iraqi constitution.”

This week’s military operation also dealt a severe blow to the autonomous region’s finances, which had relied heavily on revenues from exports of Kirkuk oil.

Baghdad has retaken five oil fields from Kurdish forces in Kirkuk, leaving the Kurds in control of only one in the province.

The lost fields accounted for more than 400,000 of the 650,000 barrels per day that the autonomous Kurdish region used to export in defiance of Baghdad.