Israeli troops in the northern West Bank are reported to have discovered a car packed with explosives.
A military source said it is believed to have been prepared by militants from the radical Islamic Jihad movement.
The group has claimed responsibility for the bombing of a nightclub in Tel Aviv three days ago, that killed five people.
Israel is refusing to accept a denial by Syria that it was implicated in the Tel Aviv blast.
Israel's Foreign Minister, Silvan Shalom, summoned ambassadors from the European Union and member states of the United Nations Security Council to a meeting today.
The head of military intelligence, General Aharon Zeevi, briefed diplomats on the alleged connection between the attack - claimed by exiled leaders of Islamic Jihad - and Damascus, a foreign ministry source said.
However, Syria says Israel's charge is not supported by any evidence.