Rebels groups started to fire at Palestinians who were decided to enter the camp to mark the anniversary of Israeli regime's occupation of the Palestinian lands, Al-Alam reported.
The incident happened after around 1,000 refugees protesting against their expulsion by the militants from the Yarmouk camp, tried to enter the camp on Wednesday.
The militants also fired mortar shells on the protesters, injuring dozens of people, including army soldiers who rushed to the scene.
Yarmouk refugee camp has borne the brunt of the turmoil in Syria over the past months. In September 2012, twenty people were killed in a mortar attack by militants on the camp.
On February 6, a bomb attack targeted the refugee camp and on January 7, two people were killed in a sniper attack by militants at the camp.
The Syria crisis began in March 2011, and many people, including large numbers of soldiers and security personnel, have been killed in the violence.