GAZA CITY, Gaza Strip (AP) – Israeli helicopter gunships, tanks and troops tightened their grip Thursday on a northern Gaza town, killing an elderly civilian, two terrorists and a police officer in Israel’s biggest push in months to stop Palestinian rocket fire.

Amid the clashes, men between the ages of 16 and 40 were ordered over loudspeakers to gather in one of the main squares of Beit Hanoun, but few complied.

Those who arrived in the square were taken by soldiers in trucks to another area of the town and questioned to find out if they were involved in terrorist activity, said the army, which took over the town Wednesday. Some were released and others were taken for more questioning, it said.

Defiant militants kept up their attacks on southern Israel, firing homemade rockets from elsewhere in Gaza, the army said.

One rocket hit a house in the nearby Israeli town of Sderot, slightly injuring one person, the army said. Hamas militants claimed responsibility.

Prime Minister Haniyeh of Hamas said the offensive was aimed at crushing the Palestinians’ spirit.

“But we are completely sure this will fail, as all previous campaigns failed … and the Palestinians will remain steadfast,” he said.

Troops moved into Beit Hanoun on Wednesday because it was a major launching ground for the 800 rockets fired at southern Israel since the start of the year, the army said.

The fighting has killed 12 Palestinians, including at least nine militants. A 70-year-old civilian was killed Thursday, as were two militants – including a bodyguard to Mr. Haniyeh, who was not in the area at the time, relatives and security officials said.

A female police officer was shot and killed while she was trying to assist a group of residents, including some gunmen, who holed up in a mosque in the town, security officials said. Israeli troops surrounded the mosque and called on those inside to surrender, the officials said.

The army said it shot an armed person who had approached troops and also shot at a group of militants who prepared to launch a rocket at soldiers.

The raid crippled the town of 50,000, with curfews imposed on some areas, and residents of others too afraid to venture from their homes.

Helicopter gunships on two separate missions fired missiles into the town early Thursday, but no injuries were reported. About 50 tanks patrolled the streets, while other tanks fired dozens of rounds into Beit Hanoun from the other side of the Israeli-Gaza border.

Snipers, meanwhile, took up position on a dozen rooftops, while other troops carried out house-to-house searches for weapons and militants.

Terrorists fought back with small arms, hand grenades, rocket-propelled grenades and land mines.

Israeli tanks parked on the town’s main streets, and bulldozers surrounded them with sand embankments to protect them from rocket fire. Much of the town’s open space had already been razed by the army in previous operations to provide staging areas for tanks and to allow troops better visibility of militant activity.

“We will not allow Beit Hanoun to serve as a launching pad for missile attacks against Israel,” said David Baker, a spokesman for Prime Minister Olmert.

Other Israeli officials said the takeover of Beit Hanoun was expected to last only a few days and did not signal the start of a wider-scale Gaza offensive.

On Wednesday, Israel’s Security Cabinet rejected proposals for a major escalation against rocket squads and arms smuggling operations along the Egypt-Gaza border.

Israel has several reasons not to launch such an offensive now.

Mr. Olmert is to meet President Bush later this month, and is wary that a major escalation in Gaza could overshadow the trip.

A wider offensive could also harm negotiations for the release of Cpl. Gilad Shalit, an Israeli soldier kidnapped in June by militants allied with the Palestinians’ ruling Hamas party, and hinder attempts by President Abbas to form a new government acceptable to the West.

An escalation could also impede American efforts to improve security and cut down on arms smuggling at the Egypt-Gaza border.

National Intelligence Director John Negroponte met Wednesday in Cairo with his Egyptian counterpart, Omar Suleiman. Arab diplomats said Negroponte proposed that Egypt allow an American-led team of multinational peace monitors to help police the border with Gaza.

He also proposed that CIA counterterrorism experts assist in efforts to halt cross-border smuggling, said the diplomats, who insisted on anonymity because of the sensitivity of the matter.

The takeover of Beit Hanoun was the latest in a series of Israeli incursions into Gaza, first launched after Shalit’s capture.

Mr. Abbas condemned the new offensive and urged the international community to take action to halt it.