Members of the Al-Aqsa Martyrs Brigades, a militia linked to the Fatah movement, hold a rally against the plan to collect weapons from the Palestinian militant factions in Nuseirat refugee camp in southern Gaza Strip, Thursday. (AP photo)

Palestinian militant groups, including Hamas and Islamic Jihad, have agreed to extend a period of "calm" with Israel as long as it meets certain conditions.

Palestinian President Mahmoud Abbas had been meeting near Cairo with leaders from 13 militant groups to persuade them to agree to a one-year ceasefire.

"Attendees agreed to maintain the recent calm in exchange for Israel's commitment to stop all forms of attacks and release prisoners," said the statement issued Thursday.

The group released its final statement after 48 hours of talks, but they couldn't agree on how long the period of calm should last.

A statement from Israeli Prime Minister Ariel Sharon's office called the move "a positive first step." Sharon's office said he made the remarks during a phone call with Egyptian President Hosni Mubarak, who hosted the talks.

Abbas had been trying for a more formal agreement from Islamic Jihad and Hamas, who had said they weren't bound by a Feb. 8 deal reached by the Palestinian and Israeli leaders.

The brief period of calm that followed that ceasefire was shattered by a suicide bombing on Feb. 25 at a nightclub in Tel Aviv that killed five Israelis. Islamic Jihad claimed responsibility for the blast.

Israel said it would continue to meet the conditions of the Feb. 8 agreement. It also demanded Abbas disarm Palestinian militant groups.

Abbas needs the truce to persuade Israel to withdraw from more West Bank towns.

The February ceasefire calls for Israel to hand over control of five West Bank towns to Palestinian security forces. Israeli troops left Jericho on Wednesday, the first of the five towns.