Jihadists who took over large areas of northern Iraq Thursday have forced 100,000 Christians to flee and occupied churches, removing crosses and destroying manuscripts, Chaldean Patriarch Louis Sako said.

“There are 100,000 displaced Christians who have fled with nothing but their clothes, some of them on foot, to reach the Kurdistan region,” he told Agence France Presse.

“This is a humanitarian disaster. The churches are occupied, their crosses were taken down,” said Sako, the leader of Iraq’s largest Christian denomination, which is aligned with the Roman Catholic Church.

He added that up to 1,500 manuscripts were burnt.

Pope Francis later called on the international community on Thursday to protect the mostly Christian communities of northern Iraq fleeing the jihadist advance.

A statement delivered by his spokesman said the pope joined the urgent appeals for peace from bishops in the Middle East and called on the international community to “ensure the necessary help” reaches people fleeing fighters from the Islamic State (IS) extremist group.

The 77-year-old pontiff “calls on the international community to protect all those affected or threatened by the violence, and to guarantee all necessary help” to those forced to flee their homes, “whose fate depends entirely on the solidarity of others.”

“The Holy Father renews his spiritual closeness to all those who are suffering through this painful trial, and makes the impassioned appeals of the local bishops his own,” the statement said.

The Islamic State (IS) group, which swept across much of Iraq’s Sunni heartland two months ago, attacked several towns and villages east of its main hub of Mosul, the country’s second city.

Among them was Qaraqosh, Iraq’s largest Christian town with a population of around 50,000, and several surrounding areas that were previously controlled by the Kurdish peshmerga force.

Fleeing residents reached by phone as they tried to enter the neighboring autonomous region of Kurdistan confirmed the jihadist takeover.

AFP could not immediately verify the current status of those towns, which witnesses said have been completely emptied of their usual population.

“Daash (IS) militants last night attacked most villages in the Nineveh plains, firing mortar rounds and seizing some of them,” Sako said, speaking from his base in Kirkuk.

“The government is unable to defend our people, as is the Kurdistan government. They need to work together, receive international support and modern military equipment.”

“Today we appeal with lots of pain and sadness, to all people of good will, the U.N. Security Council, European Union and relief organisations, to help those people who are facing mortal danger,” Sako said.

“I hope it is not too late to avoid a genocide,” he added.