Palestinian gunmen ambushed an Israeli army patrol in a West Bank (search) town after sundown Sunday, killing three soldiers, the military said, the most serious attack in the area in months.

The deadly attack came a few hours after Palestinians in Gaza fired rockets at Israeli towns, and Israeli forces wound up a phase of a wide-ranging operation in a Palestinian refugee camp on the Egyptian border.

In a statement, the military said Palestinians ambushed an Israeli army foot patrol in the Palestinian village of Ein Yabrud, east of the West Bank town of Ramallah (search). Three soldiers were killed and another was seriously wounded.

A spokesman for the Al Aqsa Martyrs' Brigades (search), loosely linked to Palestinian leader Yasser Arafat's Fatah movement, told The Associated Press its members carried out the ambush.

"A group of our fighters attacked an Israeli patrol in Ein Yabrud, killing and injuring many soldiers," he said by telephone, speaking on condition of anonymity.

The area has been the scene of frequent Palestinian gunfire attacks against Israeli military and civilian vehicles.

Israel TV said that because of the severity of the attack, Israeli forces were likely to enter Ramallah, where Arafat has been trapped in his headquarters for nearly two years.

Soldiers imposed a curfew on Ein Yabrud and were searching for the attackers, who escaped.

The last serious attack of its kind in the area was in February last year, when four Palestinian gunmen opened fire an Israeli military checkpoint at nearby Ein Arik, killing six soldiers before escaping.

Earlier Sunday, Palestinian militants fired a barrage of homemade rockets from Gaza into Israel, one of the largest salvos in months.

No one was hurt in the barrage of Qassam rockets, relatively small and primitive weapons. Three exploded in the town of Sderot, a frequent target less than a mile from the Gaza border fence, and others fell near smaller communities, the military said.

Palestinian militants make the rockets in Gaza workshops. They have a range of about five miles. Although no one has been killed in the attacks, Sderot residents and officials have called on the government to take action to stop the salvos.

In the past, similar rocket attacks have prompted Israeli military reprisals. An army spokesman declined to discuss plans for an Israeli response but said the military is always prepared to defend its citizens.

The military said last week, militants fired nine Qassam rockets, but only three landed in Israel, causing no damage or casualties.

Also Sunday, Israeli forces wound up another phase of a large-scale operation in another part of Gaza -- near the Egyptian border. However, Israel's defense minister indicated it was just a brief pause in a larger mission, and before midnight, Israeli forces re-entered the camp, witnesses said.

Soldiers swept through the Brazil section of the sprawling Rafah refugee camp for four days, and troops continued operating in other parts of the border area.

Israel launched its broadest military operation in six months in the Rafah area of Gaza on Oct. 10, six days after an Islamic Jihad homicide bombing in a Haifa restaurant killed 21 people.

Soldiers moved into the Brazil camp last Thursday, the third part of the camp to be targeted. Troops demolished at least 15 homes in the Brazil neighborhood, killing four gunmen and four bystanders, witnesses said.

Troops left behind roads destroyed by tanks and wrecked water pipes, residents said. Electric and telephone cables also were torn apart, they said.

Israel claims Palestinians use tunnels -- sometimes hidden under homes -- to smuggle arms from Egypt into the Gaza Strip. The military has said it has intelligence warnings that the Palestinians might be trying to smuggle more advanced weapons, such as anti-aircraft missiles.

During the entire Rafah operation, 14 Palestinians -- including two children and a woman -- were killed.

About 114 homes were destroyed at the start of the Rafah military operation, leaving about 1,240 Palestinians homeless, according to the U.N. Relief and Works Agency, which aids Palestinian refugees.

Israeli Defense Minister Shaul Mofaz told the Cabinet on Sunday that troops uncovered four tunnels in the Rafah area and the raids would continue, said a senior government official who attended the meeting.

In the West Bank town of Jenin, meanwhile, troops backed by tanks and armored jeeps raided offices of the militant group Islamic Jihad, confiscating computers and documents, witnesses said. Two militants were arrested, witnesses and the army said.

The militants were planning homicide attacks in Israel, the army said.

Also Sunday, Israel's army used emergency orders to call up five reserve battalions -- about 1,800 soldiers -- to replace soldiers serving in the West Bank and Gaza Strip. Such short-notice call-ups are unusual. Israel Radio said the reason was an increase in intelligence warnings of terror attacks.