Olmert said he had ordered the army to prepare for a major offensive in Gaza. (Reuters)

OCCUPIED JERUSALEM — Israel threatened on Monday, June 26, to topple the Palestinian government unless a soldier taken hostage during a resistance attack a day earlier is released alive.

"We will make sure that the Hamas government ceases to operate if the kidnapped soldier is not returned to us alive," a high-ranking Israeli security official told Agence France-Presse (AFP) on condition of anonymity.

The threat was made by Yuval Diskin, the head of Israel's Shin Beth domestic security agency, to Palestinian President Mahmud Abbas on Sunday, June 25, the source said.

The Palestinian government has denied any link to the operation and called on those holding the soldier to treat him well.

An Israeli soldier was kidnapped during a Palestinian attack on an Israeli army post on the Gaza Strip border Sunday.

Two Israeli soldiers and two Palestinian resistance fighters were killed in the same attack.

Several Palestinian resistance groups jointly claimed responsibility for the attack, saying it was to avenge the Israeli killings of Palestinians.

Israel drew international criticism recently for repeated attacks that claimed the lives of many Palestinian civilians, mostly children and women.

Mohammed Jamal Roqa, 5, Sania al-Sharif, six, and Bilal al-Hissi, 16, were killed in an Israeli air attack on Tuesday, June 20, in the Gaza Strip.

Israeli warplanes bombarded Gaza city on Tuesday, June 13, killing at least eleven Palestinians, including three children, and wounding tens others in the deadliest air strike this year.

Israeli shelling killed seven Palestinians on Friday, June 9, while enjoying a picnic on a beach in northern Gaza.

Ready to Attack

Israeli Prime Minister Ehud Olmert said on Monday he had ordered the army to prepare for a major offensive in the Gaza Strip.

"Yesterday I instructed the heads of the army to deploy our forces in order to be ready to prepare for a prolonged and extensive military operation," he said.

"We will reach everyone, anywhere and they know. There will be no immunity for anyone," Olmert threatened.

The Israeli army has amassed tanks, ground troops and artillery outside the Kerem Shalom crossing that separates Israel from Gaza Strip, waiting for the green light to move in, a security source told AFP.

Although Israel's security cabinet decided Sunday night to put off any major offensive until the kidnapped soldier is recovered, it said it would take "all necessary actions" to secure his release.

Top Israeli security officials are expected to meet again on Tuesday -- a deadline set by Olmert's inner cabinet for the soldier release -- to discuss the military options if he was not freed.

A few hours after the attack, Israeli tanks swept into the Gaza Strip in the largest ground operation since the occupation forces withdrew from the impoverished coastal strip last September.

Tanks and armored vehicles crossed into the Gaza Strip near Kerem Shalom to hunt down the attackers, an Israeli army spokesman said.

Israel also ordered Palestinian security forces positioned along Gaza's border with Egypt to immediately leave the area.

Israeli commandos mounted a rare raid into the Gaza Strip on Saturday, June 24, to hunt down Palestinian fighters.

Israel withdrew from Gaza Strip in September after 38 years of occupation.

Contacts

Palestinian officials said Monday they were trying to locate the kidnapped Israeli soldier.

"We are continuing our efforts to release the kidnapped soldier," one mediator told Reuters on condition of anonymity.

"As of now, we have been told that the soldier is fine. He is in good condition and he is being treated well."

An Egyptian security delegation which rushed to the Gaza Strip has established contact with the abductors through a third party, Israeli radio said.

Hamad said a number of parties, including the Egyptians, were working to secure the release of the Israeli soldier.

Ghazi Hamad, spokesman for the Palestinian government, told Israeli army radio that a number of parties, including the Egyptians, were working to resolve the standoff.

France also said it was in contact "with all the concerned parties to find a solution to this situation."

Warnings Ignored

In a related development, an initial probe into Sunday's attack showed that Israel's Shin Beth internal security service had warned the army of a possible Palestinian attack in the exact same area where the attack took place.

"We had warned the army of preparation for an attack in the sector, of a tunnel being dug and of a possible kidnapping of a soldier," a Shin Beth spokeswoman told AFP.

The Shin Bet said it had recently transmitted a verbal and written warning to all security forces on a Palestinian attempt to abduct soldiers in the area of the border crossings in southern Gaza, "between Sufa and Kerem Shalom," via a tunnel.

"The Kerem Shalom crossing was closed for this reason," the spokeswoman said.

The Israeli army had also arrested two Hamas members overnight Friday in an incursion into southern Gaza for the same reason, she added.

The rare Shin Beth statement was a stinging criticism of the Israeli army, whose chief of staff Dan Halutz admitted Sunday's event took the army by surprise.

The probe showed that the Israeli army has long been aware of the tunnel threat but never located this tunnel.