Jerusalem ? Taking aim from a hilltop, a sniper killed 10 soldiers and civilians at a checkpoint Sunday in the deadliest of a two-day string of Palestinian attacks that killed 21 Israelis.

Israel sent tanks and helicopters on retaliatory raids that hit several Palestinian Authority security targets, killing four Palestinian policemen, while Prime Minister Ariel Sharon and his Cabinet weighed additional military action.

Following the weekend bloodletting, Sharon huddled with senior government ministers and security officials and his office issued a statement just before midnight saying that the inner security Cabinet had approved military plans for ongoing attacks on Palestinian targets.

“Ministers approved an operational program presented by the army to apply constant military pressure on the Palestinian Authority and the Palestinian terror organizations,” the statement said. “Its object is to halt Palestinian terror.” It gave no further details.

Recent days have seen some of the worst carnage in months, and bitter comments by both sides pointed to further confrontations.

“There is no alternative but to put an end to (Palestinian leader Yasser) Arafat’s rule,” Israeli Cabinet Minister Dan Naveh said in remarks that are expressed with increasing frequency in Israel.

Speaking during an official visit to Mexico, Israeli President Moshe Katsav also denounced Arafat and called on Palestinians to question his leadership.

“The Palestinian people should ask which achievement their president brought to them in the last 18 months,” Katsav said in Mexico City. “He must, he should do something to stop the violence.”

The Al Aqsa Martyrs Brigades, a militia linked to Arafat’s Fatah movement, claimed responsibility for three of the four lethal attacks carried out in a 12-hour period from Saturday night to Sunday morning, including the checkpoint shooting.

Militants had vowed to strike after Israeli forces pushed into two Palestinian refugee camps in the West Bank last Thursday in search of militants believed responsible for earlier violence. During the incursions, 23 Palestinians were killed in three days, including gunmen, policemen and civilians.

“The Palestinian leadership considers the recent Israeli escalation … to be aimed at destroying peace and security in the whole region,” the Palestinian Authority said in a statement.

The Sunday morning shooting occurred at the military roadblock near the Palestinian village of Silwad. The army described it as an ambush carried out by a single sniper.

The gunman had a clear view from a hill overlooking the checkpoint. After the first Israeli was struck by gunfire, soldiers began climbing the steep hill toward the gunman and more were hit, witnesses said.

An army helicopter soon reached the area, but the assailant had escaped, said Hezi Tsur, a paramedic at the scene.

The dead included seven soldiers and three civilians. Six people were injured, the army and rescue services said.

The Al Aqsa Martyrs Brigades circulated a leaflet saying the shooting was in response to Israeli army actions in the two refugee camps.

In the Gaza Strip, Palestinian gunmen opened fire on a group of soldiers early Sunday along a road that runs on the Israeli side of the fence between the Gaza Strip and southern Israel.

One soldier was killed and four soldiers were wounded, the army said. The military wing of the radical group Islamic Jihad claimed responsibility for that attack in a telephone call to The Associated Press.

The pair of Sunday morning attacks followed a suicide bombing by a member of the Al Aqsa Martyrs Brigades Saturday night in a crowded ultra-Orthodox Jewish neighborhood of Jerusalem. The bombing killed nine Israelis and wounded dozens.