Civilians trapped in a Palestinian refugee camp in Syria's capital have fled to safer areas amid intense shelling and clashes between Palestinian armed factions and the Islamic State of Iraq and the Levant (ISIL) fighters who took over most of the camp, Syrian activists said.
ISIL fighters stormed the Yarmouk camp in southern Damascus on Wednesday, marking the group's deepest foray yet into the city.
Palestinian officials and Syrian activists said ISIL fighters were working with rivals from the al-Qaeda affiliate in Syria, the Nusra Front, the AP news agency reported. The two groups have fought bloody battles against each other in other parts of Syria, but appear to be cooperating in the attack on Yarmouk.
A Damascus-based Palestinian official, Khaled Abdul-Majid, said the fighters controlled about half of the Yarmouk camp, home to Palestinian refugees since 1957 and is located on the edge of the Syrian capital. 
Al Jazeera's Stefanie Dekker, reporting from Beirut, the capital of neighbouring Lebanon, said on Saturday that despite calls from the United Nations and activists, the Syrian government was unlikely to open a humanitarian corridor for 18,000 civilians who are still in the camp.
"It is a complex situation. The government forces control the northern part [of the camp] towards Damascus. It is their priority to keep the capital safe," said Dekker. "The fact that ISIL fighters are less than 10km away is of a huge concern. If they allow a humanitarian corridor, who will be coming out?"
A Syrian opposition group, the Syrian Coalition, called the development "extremely alarming" and called on the international community "to take concrete immediate steps" to protect the civilians of Yarmouk.
"Palestinian armed groups alongside the Free Syrian Army are fighting to prevent ISIS from establishing a foothold in Damascus," Salem Al Meslet, a spokesperson of the Syrian Coalition, said, referring to ISIL with an alternative abbreviation. He said, however, that the groups were under-equipped.
In addition to the ground clashes, Syrian forces were shelling the camp. 

The London-based Syrian Observatory for Human Rights, which monitors the Syrian conflict through a network of activists, reported a Syrian government air strike on Yarmouk, but said there was no immediate word on casualties.
Hatem al-Dimashqi, an activist based in an area just south of Damascus in Yalda, said mosques were blaring calls for blood donations in the areas surrounding the camp, including Yalda, Babila and Beit Saham as hospitals received wounded civilians from Yarmouk.
The United Nations has said about 18,000 civilians are trapped in Yarmouk, including a large number of children. The camp has been under government siege for nearly two years and has witnessed several rounds of deadly fighting between government forces and rebels.
UN aid workers have been sending food parcels into the camp in an effort to alleviate the extreme suffering inside.


Why the are HAMAS fighters not going into Syria and protect their own people from
Annihilation. They should save their own people to be the hero, otherwise why shoot rockets, missiles and fight the Israelis, when they are not endangering the Palestinians.