Abbas told top officials from his Fatah party that he intended to go ahead with his plan to call early elections -- a move rejected by Hamas when it was first announced in mid-December, sparking internecine bloodshed.

"I will not go back on holding early parliamentary and presidential elections," Eissa Karaqaa, a senior Fatah official in Bethlehem, quoted Abbas as telling the Fatah closed-door meeting in the town on Sunday.

"This plan is not a tactic. All paths to forming a government of national unity are closed and there is no other choice except these elections," Abbas said, adding that Fatah should "prepare" for the polls.

The Palestinian leader first issued his call for early polls on December 16, sparking armed clashes between Fatah and Hamas supporters that killed 15 people in Gaza before a truce was reached four days later.

Simmering factional tensions boiled over into armed clashes again last Wednesday, killing 16 people and wounding more than 70 others since then.

Israel weighed in on the Palestinian tensions on Sunday, with Deputy Prime Minister Shimon Peres warning that neither Fatah nor Hamas seemed fully in control of their forces.

"Both sides are trying to prevent civil war, but I'm not sure they're in full control of their forces," Peres told reporters before the weekly cabinet meeting. "Clearly civil war would be a tragedy for Palestinians, for peace and for Israel."

In the West Bank, around 400 Palestinians protested against the internecine violence.

"No to internal fighting!" shouted the protestors, who carried signs reading "Internal fighting is the last nail in the Palestinian coffin" and "We want law and order."

Gaza remained on edge on Sunday ahead of a huge Fatah rally planned for the afternoon in Gaza City to celebrate 42 years since the party's founding.

On Saturday, Abbas upped the stakes in his face-off with Hamas, when he demanded that it disband its interior ministry's "executive force," saying it was illegal and should be integrated into existing security structures.

"The executive force (controlled by Hamas) is illegal... and will be treated as such if it is not immediately integrated... into legal security services as stipulated by basic law," said a statement from the presidency.

Hamas slammed Abbas's call as a "mistake", warned against a crackdown, and declared that it intended to more than double the size of the 5,500-strong armed force, taking it to 12,000 men.

"It's not true that the executive force is outside of the security services," Prime Minister Ismail Haniya, a key Hamas figure, said in Gaza late Saturday. "It works legally according to the orders of the interior ministry."

"There are certain people who don't want the Palestinian people to live in peace and stability. And they don't want the situation to calm down in order to create a serious and deep dialogue to reach a unity government."

Hamas deployed its "executive force" on the streets of Gaza in May two months after assuming power, despite Abbas's warnings that all armed troops needed to be integrated into security structures loyal to him.