However, after a six-hour meeting in Cairo, Arab foreign ministers also expressed support for the Palestinian parliament which is dominated by Hamas.
''We are supporting President Abbas and we are supporting the elected Legislative Assembly (parliament),'' Arab League Secretary-General Amr Moussa told a news conference.
A joint statement from the 22 Arab League members condemned what it called ''the criminal acts recently committed in Gaza''.
Hamas imposed itself in Gaza yesterday after six days of battles against Fatah forces. Despite his mandate effectively being reduced to the West Bank, Abbas named a new prime minister after firing the Hamas-led government and declaring a state of emergency.
''(The Arab ministers) asked for a return of the situation in Gaza to what it was before the recent events, the prevention of any acts of violence in the West Bank and the preservation of the unity of Palestinian territory,'' it said.
Moussa backed the idea of a new government made up of people independent of the factions. ''That would give a chance for understanding in the context of national unity,'' he said.
Three months ago Hamas brought Fatah members into a ''unity'' government in an attempt to staunch violence in Gaza.
Arab governments will set up a fact-finding committee to look into the recent events in Gaza and report back to the Arab foreign ministers within a month.
Back To Mecca Agreement?
The resolution appeared tilted towards Abbas and Fatah, reflecting the dominance of Arab governments friendly towards the United States and hostile to Islamists.
But it was softer on Hamas than an earlier statement by the Egyptian government, which condemned Hamas for taking control of Gaza on Thursday and gave Abbas stronger endorsement.
An Egyptian government statement said Hamas had undermined what it called legitimate Palestinian institutions and all Palestinians should rally behind Abbas as leader.
Another conservative Arab government, Saudi Arabia, which brokered the unity government deal between Fatah and Hamas in February, reproached both sides for breaking their commitments and pressed them to return to the agreement.
In a speech, Saudi Foreign Minister Saud al-Faisal said the latest in-fighting had served the interests of Israel.
''Today the Palestinians have come close to putting by themselves the last nail in the coffin of the Palestinian cause,'' he said. ''The Palestinian leaderships must now issue an order, not just to stop the fighting immediately but also to outlaw fighting, and to return to dialogue.'' On Lebanon, the Arab foreign ministers said they would help the Lebanese government control its borders with Syria and would provide assistance to Lebanese armed forces.
They condemned the assassination of anti-Syrian member of parliament Walid Eido, who was killed in Beirut on Wednesday.
They also promised to help Lebanon tackle the problems arising from the presence of armed Palestinians in Lebanon outside the Palestinian refugee camps, it said.