JERUSALEM, 18 July 2005 — Israel threatened yesterday to invade Gaza if Palestinian President Mahmoud Abbas doesn’t control fighters who have stepped up rocket and mortar attacks ahead of Israel’s pullout from Gaza next month.

Abbas pledged to do his utmost to stop the barrages but warned that an invasion would “sabotage everything.”

Israeli Prime Minister Ariel Sharon said all restraints are off and thousands of Israeli troops have massed along the Gaza border. The sudden escalation is the most serious threat yet to a truce that had drastically reduced violence after more than four years of Palestinian-Israeli violence.

More than 100 rockets and mortars have rained down on Gaza settlements and Israeli villages just outside the territory in the last four days. Hamas leaders say they are retaliating for Israeli violations of the truce, declared Feb. 8, but one leader said the main reason for the barrage was to show that Israeli settlers were fleeing Gaza because of the rockets and not Israel’s decision to evacuate the territory.

In violence yesterday, Israeli soldiers killed a Hamas leader and Palestinian infiltrator, and the Israeli air force fired on a car in northern Gaza, wounding a bystander. The military said it targeted Palestinians on their way to firing rockets, but missed. Two Israelis were seriously wounded in a Palestinian mortar strike on a Gaza settlement.

Soldiers and tanks were poised to cross the Gaza border fence. Large-scale raids have often followed rocket and mortar barrages, but not since the truce went into effect.

Sharon told his ministers at the start of a weekly Cabinet meeting, “I spoke to the heads of the defense establishment ... and informed them that there are to be no restraints on our operations.”

Defense Minister Shaul Mofaz told the meeting that Israel would launch a “massive, prolonged and intricate” military strike if the Palestinian Authority does not stop the attacks.

Palestinian negotiator Saeb Erekat warned that an Israeli invasion of Gaza “will have a disastrous impact on the disengagement plan, and all efforts to make it a successful and smooth and peaceful disengagement,” referring to the planned pullout.

Despite the tough talk, there were signs that both sides prefer to uphold the truce. Abbas publicly called on groups like Hamas and Islamic Jihad to stop their attacks, and Israeli officials said Israel is reluctant to stage a full-scale military strike for fear of being bogged down in the coastal strip before the evacuation.

Abbas told reporters at his Gaza headquarters yesterday evening, “We are going to do our utmost to stop these rockets.”

However, he said, he did not know how long it would take. He said US officials told him of Israel’s intention to invade Gaza, warning, “If this happens, this will sabotage everything.”

The Palestinian leader blamed Israel for the tension. “Israel does not want peace or security, but we don’t want to be dragged to their playground,” he said. “Maybe they are looking for an excuse to delay the withdrawal.”

Sharon has pledged not to pull out under fire — clarifying that he would stop the fire, not the withdrawal.

Egyptian officials were mediating, and US Secretary of State Condoleezza Rice was planning a quick trip to the region to salvage the truce.

After meeting the Egyptians, Hamas official Said Siyam said differences among Palestinians can be resolved peacefully. “The internal conflict has passed, and all issues within the Palestinian internal society can be solved through dialogue,” he said, repeating the Hamas position that it is committed to the truce but has the right to retaliate for Israeli violations. A confrontation was developing in another front: Police refused to give a permit for a mass march of settlers and their backers toward Gaza today. Settler leaders say tens of thousands are to converge on Gaza to try to block the pullout.

Police and settlers negotiated through the day, but the talks broke down when settlers refused to declare a time when the protest would end.