The committee said forces loyal to Syrian President Bashar Assad shelled al-Tadamon neighborhood, causing a huge fire on Palestine Street. Free Syrian Army rebels destroyed an army tank on the same street, the group added.

Imad Arabi, Jihad Younis, Iman Azimeh and Mahmoud Kassab were among those killed, according to the committee.

Russia on Friday said it was "deeply concerned" by reports that each side in the Syrian conflict was enlisting and arming Palestinian refugees.

"We call for the participants of the conflict in the Syrian Arab Republic to show restraint and do all possible for Palestinian refugees not to be dragged into the Syrian confrontation and for places of their residence not to become objects of hostility," the Russian Foreign Ministry said.

President Mahmoud Abbas has asked the United Nations and Russia, one of Assad's last remaining allies, to work to protect Palestinians in Syria.

The Russian Foreign Ministry statement said the plight of refugees in Syria "shows the relevance of a speedy overall Israeli-Palestinian settlement, an integral part of which must be a just solution to the problem of Palestinian refugees".

UNRWA chief Filippo Grandi on Tuesday told a UN committee that most of the 518,000 Palestinian refugees in Syria were directly affected by the conflict in Syria and a significant number had been killed, injured and forced to flee.

"It is with extreme concern that we observe Palestine refugees in Syria being progressively engulfed in the conflict," said Grandi, commissioner-general of the UN agency for Palestinian refugees.

He added: "Prior to the conflict, Palestine refugees in Syria were already among the poorer strata of society. This pre-existing vulnerability is profoundly aggravated by the impact of the war."

The UN official said some Palestinian refugees had been sent back from neighboring countries and stressed that "Palestine refugees leaving Syria for temporary protection are fleeing the same grave risks and dangers as other refugees."

"In spite of the relatively small number of Palestine refugees that have left Syria, their plight sadly confirms our view that -- no matter how long they have lived in host countries and how hospitably they have been treated -- they remain extremely vulnerable and exposed to the shocks of crises, given the centrality and sensitivity of the Palestinian question in the regional context."