Demonstrators, who are furious over an Israeli airstrike in Qana that killed up to 60 civilians, protest outside the United Nations building in downtown Beirut yesterday. -Xinhua/Reuters

Angry Palestinian demonstrators stormed an office for the United Nation in Gaza City on Saturday evening in a protest against Israeli "massacre" on Lebanese civilians.

Five Palestinians were wounded and five others reported to be arrested during their clashes with the police and the Presidential Guard, known as Force 17.

The clash erupted after the demonstrators broke into the representative office of the UN Special Envoy to the Middle East Process in Gaza City, said witnesses.

However, there was no word from official sources, while some informal security sources said that the five arrested were militants from the Islamic Jihad (Holy War).

The rally was called by the Fatah movement led by Palestinian President Mahmoud Abbas and the Islamic Jihad to protest against the Israeli airstrike at a building in Qana village in southern Lebanon, during which about 60 civilians were killed.

According to the witnesses, the Presidential Guard was the first to counter the demonstrators when they tried to broke into the UN office which is less than 1 kilometer away from President Abbas' Gaza headquarters.

Earlier, members and supporters of the governing Islamic Resistance Movement (Hamas) also took to the streets to protest what they called a massacre against the innocent brothers in Lebanon.

They headed and marched in front of the Palestinian Legislative Council (PLC).