JERUSALEM — Israeli security forces remain on alert for terrorist attacks after the assassination of the leader of the fundamentalist Islamic Jihad movement.

Israeli security officials placed restrictions on Palestinian travel to and from the Gaza Strip on Monday after they received reports of a planned suicide attack against Israel.

Islamic Jihad officials vowed to take revenge against Israeli targets around the world after the head of Islamic Jihad, Dr. Fathi Shakaki, was assassinated Oct. 26 in Malta.

Israel declined to comment on whether it was behind the shooting.

Islamic Jihad said in a statement issued in the Gaza Strip that "this horrendous crime will make every Zionist, wherever they are on the face of the earth, a target to our amazing blasts and our bodies exploding in anger" — an apparent allusion to renewed suicide bombings of Israeli targets.

The Palestinian Authority called on Islamic Jihad to refrain from retaliation, saying that it could ultimately hurt the self-rule government.

But Islamic Jihad officials rejected the Palestinian appeal. In its statement calling for revenge, the group vowed to "set the ground on fire underneath the feet of the criminal Zionists."

Under the Israeli restrictions imposed Monday, the age of Palestinian workers allowed to enter Israel from Gaza was raised to 35 and all Palestinian vehicles were barred entry to the Jewish state.

Students from Gaza were not allowed to enter Israel, and Palestinian residents of the West Bank and eastern Jerusalem were not permitted to enter Gaza.

Israel stopped short of imposing a full closure on the West Bank and Gaza.

Palestinian officials say the closures increase economic hardship and create unrest and instability among the Palestinians, many of whom depend on jobs in Israel to earn a livelihood.

The threats of renewed violence by Islamic Jihad came days after the spiritual leader of the militant fundamentalist Hamas movement called for abandoning terror.

In an interview from his jail cell last Friday, Sheik Ahmed Yassin asked his followers to stop attacks on Israel and run in the upcoming Palestinian elections.

Yassin, a Muslim cleric and wheelchair-user serving a life sentence in Israel for ordering the deaths of Palestinians suspected of collaborating with Israelis, founded Hamas in December 1987.

The Islamic Jihad statement was the first confirmation that the man shot outside a hotel in Malta was indeed Shakaki.

Authorities in Malta initially reported that a man identified as Libyan businessman Ibrahim Shawesh had been shot five times in the head by two men on a motorcycle.

On Sunday, Maltese officials identified the victim as Shakaki after Israeli police provided fingerprints of the Islamic Jihad leader.

The Maltese authorities described the assassination of Shakaki as a "professional job."

Shakaki, 43, had reportedly stopped over in Malta on his way back to Syria from Libya, where he had met with Libyan leader Moammar Khadafy to discuss Tripoli's recent expulsion of Palestinians from Libyan soil.

According to some reports, Islamic Jihad and Khadafy conspired together on the expulsions, meant to undermine the Palestinian Authority's peace moves with Israel.

While declining to say whether Israel was involved in the shooting, Israeli leaders said they were not sorry Shakaki was dead.

Prime Minister Yitzhak Rabin told reporters that Shakaki had led "a murderous terrorist group that committed murderous attacks against citizens."

And Foreign Minister Shimon Peres said he did not think the killing would be detrimental to the peace process.

"I think his business was murdering, so if there will be one murderer less, I don't see how it's going to affect the peace process," he said.

Peres added that he was not concerned about Islamic Jihad threats of terrorist attacks.

"The threats existed all the time," he said. "There's nothing new about that."

Shakaki, a medical doctor who was born in Gaza, established Islamic Jihad in the early 1980s.

After being expelled by Israel to Lebanon in 1988, Shakaki set up his base of operations in Syria.

Islamic Jihad, which violently opposes the Israel-Palestinian peace accords, claimed responsibility for the Jan. 22 suicide bombing near Netanya, in which 21 people were killed and 60 others wounded.

The group also claimed responsibility for the April 9 bombing of a bus near the Jewish settlement of Netzarim in Gaza. Seven Israeli soldiers, along with American student Alisa Flatow, were killed in the explosion.

Islamic Jihad officials, meanwhile, announced the appointment of Ramadan Abdallah Shallah as Shakaki's successor. Shallah reportedly founded Islamic Jihad with Shakaki in the early 1980s.

Meanwhile, a commercial strike was observed by Islamic Jihad followers in parts of the West Bank on Sunday and Monday.

Israeli soldiers fired tear gas to disperse crowds of Palestinians in the West Bank towns of Hebron and Nablus on Monday.

Some 1,000 students demonstrated at Bir Zeit University in the West Bank, holding aloft placards denouncing Israel.

University students also demonstrated Sunday in Gaza, and vowed revenge for Shakaki's death.