They do it! ISIS is now "armed groups" for al-Qazeera:
"An estimated 60 percent of Syria's Yarmouk refugee camp for Palestinians has been destroyed as government forces and their allies escalate a military offensive against armed groups in the Damascus-area camp, according to a watchdog group.
Citing an eyewitness, the UK-based Action Group for Palestinians of Syria said on Friday that the destruction has largely been caused by barrel bombs, missiles and shelling.
The group said that "families were buried under the rubble of their homes" in Yarmouk, where an estimated 3,000 people still reside."
Then:
"On April 19, the Syrian government and allied Palestinian armed groups launched a renewed military offensive against armed groups - including the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) - in the besieged refugee camp."
And, who wonders:
"On Thursday, the Palestinian political party Hamas issued an appeal to all sides involved in the fighting to reach a truce.
That same day, the UN agency for Palestinian refugees (UNRWA), warned of "catastrophic consequences" of the intensified violence in Yarmouk and the surrounding areas, including al-Hajar al-Aswad and Yelda."
Estimated 60 percent of Yarmouk destroyed amid violence: Group
So Palestinians helping to liberate their camp (it is actually a district) from ISIS is a catastrophe for Hamas and UNRWA.