Fourteen Palestinian refugees were reported killed and another 43 injured on Monday, a report from the Palestinian government's WAFA news said.

The victims were part of a massive group in Al-Yarmok, an unofficial Palestinian refugee camp in the Syrian capital of Damascus, mourning the death of between 10-23 Palestinians by Israeli fire on the Golan Heights ceasefire line the day before.

Angered over the failure of camp leaders to organize demonstrations marking the Naksa, the anniversary of Israel's occupation of the West Bank, Gaza, and Golan Heights, an estimated 100,000 mourners were said to have attacked the headquarters of the Popular Front for the Liberation of Palestine - General Command.

Reports said the party's leadership refused to participate in the Naksa Day events, but encouraged camp residents to do so. Tensions had already been high in the camp, according to Palestinian sources in the area, because of a divide in the support of leaders for the Syrian regime, and many camp residents who support pro-opposition groups.

Militants with the PRFL-GC reportedly opened fire on the crowd, who were taken to a local camp hospital for treatment. The report cited hospital staff saying 14 were pronounced dead.

During the clash, mourners reportedly set fire into the PFLP-GC headquarters, and demanded condemned the group for its use of weapons against the crowd.

On Sunday, thousands gathered on the Syrian-Israel ceasefire line in the Golan Heights and attempted to breach the frontier in a march of Palestinian refugees and their supporters demanding an end to Israel's occupation of the West Bank, Gaza and the Golan Heights, taken over 44 years ago that day in the 1967 War.

Syrian television said Israeli soldiers fired on the unarmed group, killing 23, while Israel says 10 were killed by Syrian landmines along the ceasefire line.

The event was a repeat of 15 May protests marking the Nakba, when some 800,000 Palestinians were displaced from their homes and villages during fighting that accompanied the declaration of the state of Israel. Four from Syria and ten from Lebanon were killed by Israeli fire in protests on that day.