SYRIANS AND

Palestinian allies ready to attack Islamic State holdouts if talks fail.

DAMASCUS, Syria — Syrian troops and allied Palestinian fighters are preparing for an offensive on the last Islamic State bastion in the capital if talks on an evacuation deal fall through.

The extremists seized most of the Yarmouk refugee camp in 2015 after months of heavy fighting. The built-up residential area on the southern edge of Damascus was once home to about 200,000 Palestinians, mainly refugees from the 1948 war with Israel and their descendants — as well as tens of thousands of middle-class Syrians.

Today there are some 2,500 Islamic State fighters in Yarmouk and nearby neighborhoods, according to Khaled Abdul-Majid, a leader of the government-allied Palestinian Resistance Factions Coalition. He said the battle would begin within days if the militants do not agree to be evacuated.

Yarmouk is one of the last pockets held by the Islamic State, after the extremists were driven from nearly all the territory they once controlled in Syria and Iraq. It is also the last part of the capital outside government control, after rebels evacuated the eastern Ghouta suburbs following a fierce government offensive and an alleged poison gas attack.

The government has proposed a similar evacuation deal for the Islamic State. But instead of sending the militants to the northern rebel-held province of Idlib, it would dispatch them to a pocket of territory near Israel and Jordan controlled by an Islamic State affiliate, according to the Britain-based Syrian Observatory for Human Rights. The Observatory, which closely monitors the war through sources inside Syria, said the Islamic State has demanded to go to Idlib instead.

Abdul-Majid said the most extreme of the Islamic State fighters reject any settlement, but he insisted they have no choice but to leave to southern Syria or face a government offensive. Insurgents from other groups in nearby neighborhoods, however, would be allowed to go to Idlib or take part in a government amnesty.

There are about 5,000 civilians in Yarmouk, Abdul-Majid said. About 40,000 Syrians and 4,500 Palestinians displaced from Yarmouk are living in the adjacent neighborhoods of Babila, Yalda and Beit Sahem, which are controlled by other insurgent groups. Tadamon, which is partly controlled by the Islamic State, is home to 3,000 civilians, and there are 20,000 residents in Islamic State-held Hajar Aswad, the vast majority of them family members of Islamic State fighters, he said.

“Despite all the preparations and reinforcement we hope that there will be a deal and not a battle,” he said. “We don’t want further destruction in the camp after all the battles over the years.”

Any military operation would be led by Syrian troops, pro-government Palestinian factions and the paramilitary National Defense Forces.

“I don’t think that the battle will be difficult and long,” Abdul-Majid said, estimating that the fighting would only take a few days.

Syrian President Bashar Assad’s forces have retaken a number of cities and towns from the Islamic State as well as Syrian rebel groups since Russia entered the war in 2015, providing crucial air support.