A UN agency chief said Sunday he was deeply concerned for civilians stuck in a Damascus refugee camp after it was stormed by the Takfiri group ISIL.

A UN agency chief said Sunday he was deeply concerned for civilians stuck in a Damascus refugee camp after it was stormed by the Takfiri group ISIL.

"We remain very worried for refugees and civilians inside Yarmouk. We are very determined to provide assistance to those who have decided temporarily to leave the camp and find shelter elsewhere," said Pierre Krahenbuhl, who heads the UN agency for Palestinian refugees UNRWA.

On April 1, ISIL launched an assault on Yarmouk, which was once a vibrant home to 160,000 Palestinians as well as Syrians but now has fewer than 18,000 residents.

Krahenbuhl spoke while visiting a school in the Tadamon neighborhood, where displaced Palestinians from Yarmuk have sought refuge.

He said UNRWA remained "determined" to bring aid to Palestinians who have fled to Yalda and Babila, two neighborhoods on the outskirts of Yarmouk.

Krahenbuhl said that since the "dramatic changes" brought about by ISIL's assault on Yarmouk, "the focus is on how to provide assistance for people inside."

"We are also thinking about how we can we improve the ability for people who wish to leave temporarily to come out safely and to receive assistance," he said.

Krahenbuhl arrived in Damascus on Saturday on an "urgent mission" to discuss aid to civilians fleeing the violence in Yarmouk.

He was set to meet with Syrian government representatives as well as the UN's deputy special envoy Ramzy Ezzeldin Ramzy.