Israel's Shin Bet (search) security service has tightened protection of the prime minister, legislators and parliament ahead of next week's crucial Knesset vote on a Gaza Strip (search) withdrawal, security officials said Wednesday.

In the countdown to the decision, Israel's political climate has become increasingly explosive. Some withdrawal opponents have harshly attacked Prime Minister Ariel Sharon (search), denouncing him as a dictator who is endangering Israel.

Security officials said the Shin Bet is on high alert regarding possible attacks on Sharon, and he was ringed by an unprecedented number of bodyguards this week.

Jewish settler leaders said they would stage a mass rally outside parliament during the vote, which is set for Tuesday. Sharon is expected to win a majority, with the help of the moderate opposition Labor Party. Settlers have been pushing for a national referendum, but Sharon has rejected the idea as a stalling tactic.

In the context of the withdrawal plan, Israel's military is increasingly concerned about calls by prominent rabbis to mutiny. Rabbis have asked religious soldiers to refuse orders to participate in the dismantling of settlements; in the withdrawal, nearly 9,000 settlers would be removed from their homes.

Defense Minister Shaul Mofaz and his army chief, Lt. Gen. Moshe Yaalon, on Tuesday called on rabbis to withdraw their ruling.

"The Israeli Defense Forces is what unites the different parts of this nation," Mofaz said. "Refusal will lead to disintegration. I urge the rabbis who called for refusal — take it back, don't tear us apart."

Some of the army's key officers are observant, and identify with the Jewish settlement movement. Military analysts said if a significant number of religious soldiers refuse to observe orders, the army could become paralyzed.

Sharon was to present his plan of "unilateral disengagement" from the Palestinians to parliament on Monday, followed by a vote Tuesday. The plan will be sent to a committee, and be brought for a second and third vote in coming months.

Mofaz met Wednesday with Rabbi Ovadia Yosef, leader of the religious Shas party, to try to shore up support for the Gaza withdrawal. Shas is a hawkish opposition party and Yosef has been cool to the disengagement plan. Mofaz tried to persuade the rabbi to instruct Shas legislators to abstain.

On the day of the vote, thousands of settlers were expected to assemble outside parliament. Schools in settlements are to be closed to increase attendance at the rally, settler spokesman Yehoshua Mor-Yosef said.

Most protesters will wear orange T-shirts, a symbol of the Gaza settlements, and the main slogan will be "Sharon is tearing apart the nation," Mor-Yosef said.

Security around Sharon has been increased significantly in recent weeks. During a visit to parliament this week, Sharon was ringed by an unprecedented 10 bodyguards, rendering him almost invisible behind a human shield — and that in a place that is already heavily protected.

Sharon has been evasive about whether he is wearing a bulletproof vest — customary protection for Israeli prime ministers since the assassination of Yitzhak Rabin (search) by an ultranationalist Jew in 1995. Sharon has joked that he is too big to find a vest that fits him.

Shin Bet agents have also run decoy motorcades to confuse possible assailants.

Israeli security officials said that in the days leading up to the vote, certain hallways in parliament will be blocked as Sharon passes through.

The Shin Bet has also beefed up security at Jerusalem hotels where ministers and legislators stay when the Knesset is in session. In 2001, Palestinian militants killed an Israeli Cabinet minister in a shooting ambush in a hotel hallway.

In other developments:

— Two Palestinians were killed Wednesday by Israeli soldiers. In one incident, a man was in his home in the Rafah refugee camp when he was hit by random fire, his family said. In the second shooting, a militant of the Islamic Jihad group was killed as he tried to attack an army outpost near the Rafah camp, the army said.

— Late Tuesday, Palestinians fired at an army base in the West Bank, killing a soldier in his tent. The Al Aqsa Martyrs' Brigades, a militant group tied to Yasser Arafat's Fatah faction, claimed responsibility. The soldier was the 1,000th person to be killed on the Israeli side in four years of violence, according to an Associated Press count. During the same period, 3,265 people were killed on the Palestinian side.