The truce between the Fatah and Hamas factions appears to have well and truly collapsed after fresh fighting claimed at least 20 lives in the region.

However a Hamas spokesman assured that a fresh truce would be hammered out by Friday even as Palestinian Authority President and Fatah chief Mahmoud Abbas and Hamas political chief Khaled Meshaal are scheduled to meet in Saudi Arabia next week.

Hamas and Fatah have been trying to reach an agreement to form a unity government ever since the former won the parliamentary elections last year. However constant infighting has left both factions wary of each other.

Meanwhile Abbas appealed for calm. "I call upon everyone, regardless of their affiliation, to stop this bloodletting," Mr Abbas said.

At least four Fatah-affiliated security officers have been killed in the last 24 hours as the fighting shows no sign of abating. The United States has also asked the Quartet of Middle East mediators to meet in Washington in order to resolve the issue.