Jerusalem ? Dozens of Israeli tanks rolled into the West Bank’s largest city early Friday, after Palestinian infiltrators seized a house at a nearby Jewish settlement and killed a mother, three of her children and a security officer.

To the north in Jenin, during a break in a three-day curfew, shooting and tank fire near a market area killed four Palestinians, including three children, and wounded 24 others, according to Palestinian hospital officials.

The Israeli army spokesman’s office said three Palestinians were killed and 10 injured when soldiers fired two tanks shells to disperse what they thought was a crowd of curfew violators. An initial inquiry “indicates that the force erred in its action,” and an investigation was continuing, the army said.

As Israeli troops and tanks took up positions in the city of Nablus, Prime Minister Ariel Sharon planned to convene his security Cabinet to discuss Israel’s next steps.

“This is a horrendous attack, and there always has to be a response for such things,” said Sharon spokesman Raanan Gissin.

Public Security Minister Uzi Landau said Israel must hit hard at the Palestinians “to topple the Palestinian Authority and to kick (Palestinian leader Yasser) Arafat and his close associates out of this region.”

But Foreign Minister Shimon Peres warned that would be a mistake. “There won’t be anyone to talk to, anyone to turn to,” he said. Peres and Landau were interviewed Friday on Israel Radio.

There was no immediate Palestinian Authority comment about the attack on the settlement.

At an industrial park near Erez crossing between Israel and Gaza early Friday, a Palestinian threw a grenade at Israeli soldiers, who fired back, killing the attacker and two Palestinian workers, the military and Israel Radio said.

A 10-year-old boy was killed when Israeli troops opened fire at a group of Palestinian children and an Associated Press reporter and photographer on a Gaza road as soldiers tore down a Palestinian police post.

Israeli military sources, speaking on condition of anonymity, said soldiers were ordered to destroy a police post that was used for firing anti-tank shells at an Israeli outpost, and soldiers fired at suspicious targets. The sources said the reporters were not a target.

The attack on the Itamar settlement late Thursday brought to 33 the number of Israelis killed in Palestinian shootings and bombings this week. Sharon decided earlier this week _ in a major policy shift _ that troops would reoccupy some Palestinian land for every attack and remain there until terror stops.

On Thursday, the Israeli army began calling up reserves for what TV reports said would be a military campaign to be called “Determined Path.” The scope of the operation was not clear.

In late March, Israel launched operation “Defensive Shield,” the largest-scale offensive in 20 years, in which troops took over most West Bank towns for several weeks. That offensive was aimed at Palestinian militias but failed to crush them.

Events in Itamar began shortly after 9 p.m. Thursday when two Palestinians armed with grenades and assault rifles entered the house of the Shabo family.

The attackers killed Rachel Shabo, 40, and her sons Neria, 16, Zvi, 12, and Avishai, 5. The settlement’s security chief, who rushed to the scene, was also killed. Eight people in the house were wounded, including Shabo’s 11-year-old son, who was in serious condition.

Israeli commandos stormed the house, killing one infiltrator. In the exchange of fire, the two-story house went up in flames. Soldiers conducted searches after witnesses said a second attacker jumped out a window escaped.

In a phone call to The Associated Press, the Popular Front for the Liberation of Palestine claimed responsibility. In October, the small, radical faction assassinated an Israeli Cabinet minister.

In the West Bank town of Jenin, meanwhile, Palestinian security officials said a 14-year-old Palestinian boy was killed and seven other people were wounded when Israeli troops blew up an empty building early Friday. The blast caused a nearby building to collapse, the security officials said.

The Israeli army said its forces had blown up a bomb factory found in the town during the night.

In Nablus, witnesses said about 50 tanks and a number of armored bulldozers entered the outskirts of the city from four directions. Israeli tanks fired sporadic bursts of machine-gun fire, but there was no apparent resistance, and soldiers used loudspeakers to declare a curfew, witnesses said.

The Israeli army would not immediately comment.

Earlier Thursday, Israeli forces rounded up Palestinians for questioning in Jenin, Qalqiliya, Bethlehem and Beitunia, a suburb of Ramallah, Palestinians and the military said. Israeli forces tightly encircled Tulkarem, as Israel Radio broadcast alerts about suicide bombers about to attack Israel.

Two bombings in Jerusalem killed 26 Israelis on Tuesday and Wednesday, leading the Israeli government to press ahead with a new policy of seizing Palestinian territories as a response to the suicide attacks.

Israeli forces set up tents in some Palestinian areas, indicating a plan to stay for at least a few days, but were not building permanent infrastructure like water pipes or electricity lines.

The violence delayed plans by President Bush to deliver a speech outlining U.S. recommendations for Mideast peacemaking. White House press secretary Ari Fleischer said Bush first wants to see Palestinian leader Yasser Arafat carry out his pledges to fight terror. “The progress the president is looking for is action,” Fleischer said.

Bush called Sharon on Thursday. Fleischer said “most of the conversation was about condolence and sympathy for what Israel is going through.” Sharon’s office would not comment. Also, U.S. Secretary of State Colin Powell talked to the foreign ministers of Egypt, Jordan and Saudi Arabia.

Israeli Defense Minister Binyamin Ben-Eliezer said that “one reserves division” has been called up to bolster Israel’s defenses. A division is about 1,200 soldiers.