TEL AVIV — The Palestinian Authority has reached a deal that would protect insurgency groups in exchange for a reduction in attacks on Israel.

Israeli officials and military commanders said the deal was reached between PA Chairman Mahmoud Abbas and the leaders of the three major insurgency groups in February 2005. They said Abbas agreed to protect the ruling Fatah movement as well as the opposition Hamas and Islamic Jihad from Israel's military in exchange for a reduction of attacks on the Jewish state.

"The deal does not mean these groups had to stop terrorism," an Israeli official said. "It just means that they can't do anything that would endanger Abbas's regime and hurt its ties with the United States."

[On Thursday, Israeli authorities bolstered security along the borders with the West Bank and Gaza Strip and reinforced police in major cities. The increased security came on the eve of the Jewish holiday of Purim, marked by street festivals.]

Officials said the agreement was endorsed by Egypt during talks between Abbas and insurgency groups in Cairo in March. They said Abbas pledged to allow insurgents to join PA security agencies or provide them with a pension.

The insurgents were also assured that the PA would not allow Israel's military to pursue insurgency fugitives in the West Bank and Gaza Strip. Officials said the PA also pledged not to demand the surrender of weapons held by insurgents or their production facilities.

Officials said Palestinian insurgency groups have reduced their activities in the West Bank and Gaza Strip. They said the PA has helped foil attacks by insurgents or insurgency groups that were not part of the understanding.

In some cases, officials said, Palestinian insurgency groups have tried to recruit Israeli Arabs to facilitate major attacks in Israel. On Thursday, Israeli authorities said an Israeli Arab confessed to receiving money from Islamic Jihad to plan a suicide attack on a Tel Aviv nightclub in February.

"Regrettably, we still don't see significant organization or sufficiently serious Palestinian activity to prevent terror, and as long as it doesn't happen, the threat exists," Israeli Chief of Staff Lt. Gen. Moshe Yaalon said on Wednesday. "And in a number of places in the West Bank, particularly in the Nablus, Jenin and Tulkarm areas, there are still active terrorist squads who intend to carry out attacks during the coming days."

Officials said Abbas has informed Israel and the United States that the PA would not restructure security agencies until the end of 2005. Abbas was said to have cited the need for approval by security commanders and Fatah to facilitate the process.

Israeli Defense Minister Shaul Mofaz said the failure of the PA to dismantle insurgency cells would not block efforts to transfer security responsibility of West Bank cities to the PA. But he said the process would be slow.

"The Palestinian rate of progress on everything regarding arrests and fulfilling their obligations has ranged from very slow to the point where nothing at all has been done," Mofaz said. "This will make it difficult for us to hand over responsibility for the additional towns."