DAMASCUS // ISIL militants infiltrated a Palestinian refugee camp in Damascus on Wednesday, the deepest foray yet by the extremist group into the Syrian capital.

Jordan, meanwhile, closed its only functioning border crossing with Syria, following heavy clashes on the Syrian side between rebels and government forces.

ISIL, which controls large swaths of territory in northern Syria, entered the Yarmouk camp from the nearby Hajar Aswad neighborhood, sparking heavy clashes with members of a Palestinian faction called Aknaf Beit Al Maqdis.

The Britain-based Syrian Observatory for Human Rights said ISIL took control of large parts of the camp. If they gain full control, they can potentially threaten the heart of the capital and the seat of president Bashar Al Assad’s power.

Anwar Raja, spokesman for the pro-Assad Popular Front for the Liberation of Palestine – General Command, said ISIL fighters had been based in the Hajar Aswad neighborhood for months. He said Wednesday’s push into the camp showed coordination between ISIL and a rival group, Jabhat Al Nusra, Al Qaeda’s branch in Syria.

“The Nusra Front opened the road for them in order to infiltrate the camp and several hours ago they entered Yarmouk,” Mr Raja said.

Yarmouk, a Palestinian refugee camp in southern Damascus, has been under government siege for nearly two years. UN aid workers have been sending food parcels into the camp, where thousands of civilians remain trapped and in desperate need of food and medicine. The camp had been the scene of fighting in the past between government forces and militants who control much of the camp.

The UN agency that supports Palestinians, known as UNRWA, said it was extremely concerned about the safety and protection of the Syrian and Palestinian civilians in Yarmouk, particularly the children.

“A variety of armed groups are engaged in fierce fighting in areas where Yarmouk’s 18,000 civilians, including a large number of children reside, placing them at extreme risk of death, serious injury, trauma and displacement,” the agency said. It demanded “an end to the fighting and a return to conditions that will enable its staff to support and assist Yarmouk’s civilians.”

Meanwhile, Jordanian government spokesman Mohammed Al Momani said the Nasib crossing was temporarily closed late on Tuesday because of clashes nearby.

“It is important for us to keep the safety for the passengers and those who are trying to cross between the two countries,” he said. “So we decided to close the border temporarily, until things calm down. Then we will open it again.”

A spokesman for rebels in southern Syria, Issam Al Rayess, confirmed that rebel fighters were trying to take control of the border crossing from Syrian authorities.

The Nasib crossing is the only functioning crossing between Jordan and Syria and is considered a crucial gateway for Syria’s government and for Syrian, Lebanese and Jordanian traders and merchants.

A Syrian foreign ministry statement said it holds Jordanian authorities responsible for “obstructing the movement of trucks and passengers and any ensuing economic or social repercussions.”

*Associated Press