On Wednesday, many Palestinian refugees escaped the camp, which is situated in the capital Damascus.
Earlier in the day, UN Secretary General Ban Ki-moon said he was “deeply concerned about all this violence taking place against Palestinian refugees in Yarmouk camp.”
He said that there were 160,000 refugees in the camp and that 100,000 of them had fled.
Palestinians started fleeing the refugee camp following deadly clashes that broke out in the area on Sunday.
Violence rose after armed men affiliated to the al-Nusra Front executed a number of Palestinian civilians in the camp.
Yarmouk and the districts surrounding it have borne the brunt of the turmoil in Syria over the past months. In September, at least 20 people were killed when mortar shells landed in the camp.
Syria has been experiencing unrest since March 2011. Many people, including large numbers of army and security personnel, have been killed in the turmoil.
The Syrian government says the chaos is being orchestrated from outside the country, and there are reports that a very large number of the militants operating in the country are foreign nationals.