ISIS entered the Yarmouk camp as Jordan closed its only functioning border crossing with the country following heavy clashes on the Syrian side between rebels and government forces.

The militants, who already control large swaths of territory in northern Syria, reportedly entered the camp from the nearby Hajar Aswad neighborhood in southern Damascus in a coordinated attack with their rivals in the Al Qaeda-affiliated Nusra Front.

According to the the UK-based Syrian Observatory for Human Rights, ISIS managed to take control of large parts of the Yarmouk camp following clashes with a Palestinian group.

If ISIS manage to gain full control of Yarmouk, the jihadis can potentially use the camp as a base from which to threaten the heart of the capital as possibly challenge Assad himself.

The Palestinian-run refugee camp has been under government siege for nearly two years.

U.N. 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 witnessed fighting in the past between government forces and militants who control much of the camp.

The Observatory reported heavy clashes in the camp between IS fighters and members of the Palestinian faction called Aknaf Beit al-Maqdis.

Anwar Raja, the spokesman for the pro-Assad Popular Front for the Liberation of Palestine said ISIS fighters entered the camp from nearby Hajar Aswad where they have been based for months.

He added that today's push came was coordinated between ISIS and their rivals in the Nusra Front, 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,' Raja said by telephone. 

It was not immediately clear why Nusra - who have repeatedly fought against ISIS over the past year - would facilitate the entry of the group into the camp.

A Syrian foreign ministry statement today said it holds Jordan responsible for 'obstructing the movement of trucks and passengers and any ensuing economic or social repercussions.'

(dailymail.co.uk)