Fearing terror attacks during the week-long Jewish Passover holiday, Israel has imposed a complete closure on the West Bank and Gaza Strip. The announcement came shortly before the start of Passover, beginning at sunset Wednesday.

The Israeli army said it had received warnings of possible terrorist attacks and decided that Palestinians would be barred from entering Israel during the Passover holiday, which ends in one week.

The only exceptions would be for humanitarian cases such as Palestinians requiring urgent medical treatment.

Israel also decided to close Gaza's Mediterranean shores to fishermen, as well as entry between the West Bank and Jordan and between Gaza and Egypt.

The decision was made amid fears that Palestinian militants would carry out attacks on the anniversary of last year's Passover suicide bombing in the Israeli seaside resort of Netanya, in which 29 people were killed.

On Monday, an Israeli court handed down life sentences to four Palestinians convicted of their involvement in that attack. All are members of Hamas, the Islamic Resistance Movement that is committed to Israel's destruction.

In a bid to prevent more such attacks, hundreds of policemen and volunteers have taken up positions in the center of the country, especially in central Netanya.

Special attention is being given to synagogues, shopping malls, outdoor markets and central bus stations.

The Israeli security establishment is also taking precautions this year across other parts of the country after receiving 56 warnings of terror attacks for Passover.

The warnings include planning suicide attacks, booby-trapped cars, bombs and the kidnapping of soldiers.

Roadblocks have also been set up around Jerusalem, which is another area deemed to be a likely target for possible terror attacks.