Army intelligence adviser Major-General Dan Halutz has also told civilians to buy up supplies of materials to seal rooms against chemical attack and suggested they replace outdated gas masks with new models.

The BBC's Lyse Doucet: "Israel is watching the situation very closely"

At a briefing in Tel Aviv, Major-General Halutz said the possibility of such an attack was "extremely low" and the measures advised were a precaution.

Meanwhile, the Prime Minister, Binyamin Netanyahu, has told Israeli radio that while Israel had no intention of getting involved in the conflict with Iraq, it retained the right of self-defence if necessary.

Patriot missiles were used during the 1991 conflict

"We have no intention of being part of this conflict, but we are preparing for every eventuality," Mr Netanyahu told Israel radio.

Mr Netanyahu convened his security cabinet, including Defence Minister Yitzhak Mordechai and Foreign Minister Ariel Sharon on Thursday to map out strategy.

Israel TV's Channel Two said Patriot batteries have been moved from sparsely populated southern Israel to central Israel and near the northern port city of Haifa.

Mr Netanyahu said US President Bill Clinton had raised the possibility of a US attack on Tuesday when he first learned that Iraq was not co-operating with UN weapons inspectors.

Gas masks distributed

The army said it would open 65 gas mask distribution stations by the end of the day that would operate around the clock.

Palestinians have been protesting against the air strikes

The army's civil defence branch also ordered factories producing masking tape and plastic sheets used to seal off "safe rooms" in homes to operate around the clock. Municipal authorities around the country have opened public bomb shelters.

Israel's Tourism Ministry said it had enough gas masks for all tourists in the country, which is gearing up for Christmas visitors to the Holy Land.

But British tourist operators evacuated hundreds of their clients from the Red Sea resort of Eilat and arranged for them to be flown home on special flights.

Israel fears it may come under attack as it did during the 1991 Gulf War when dozens of Iraqi Scud missiles armed with conventional warheads were fired at Tel Aviv. Israel endured the attacks without retaliating.

Concerns have been raised that Iraq could be capable of firing chemical or biological warheads at Israel.