In its most serious warning yet, the Israeli army told residents on Wednesday to get gas masks and buy supplies to seal a room in their house in preparation for a possible U.S.-led war in Iraq.

The warning came after weeks of preparations by Israeli officials and stepped-up U.S. military deployments in the Persian Gulf.

"As of now I want to emphasize -- get ready, renew your gas masks and finish buying equipment for sealing rooms," Brig. Gen. Ruth Yaron, the army's chief spokeswoman, said on several morning radio talk shows.

Hundreds of people rushed to gas mask distribution centers after hearing the radio announcements. Some exchanged old, tattered masks. Others were given new ones.

"Now it is official. War will begin very soon," said Abed Abarijmi, 40, an Arab Israeli who said he went to the distribution center after hearing the news on the radio. He picked up eight masks.

"I heard the news this morning," said Bashir Hassan, 28. "Now is the time to change my family's masks. They've been in my car for weeks now, but now it seems serious."

Maj. Gen. Aharon Zeevi-Farkash, chief of Israeli military intelligence, told a a parliamentary committee on Tuesday that a U.S.-led attack could come as early as next week and Saddam Hussein could retaliate by hitting Israel, but the chances of that were small.

Some Israelis were left wondering what their government really meant.

"I'm quite confused. One day they say there is nothing to worry about and the next, they make it sound like war will break out tomorrow," said Tamir Sheffel, 38.

During the 1991 Gulf War, Iraq fired 39 Scud missiles at Israeli cities, causing heavy damage but few casualties. The missiles all carried conventional explosive warheads.

Israel first distributed gas masks to its people before the 1991 conflict to guard against the possibility of an Iraqi chemical or biological attack. Since then, citizens have received periodic notices to restore the kits, which include antidotes to poison gas as well as masks -- but with the threat at a low level, most Israelis ignored them.

About 230,000 U.S. forces have already deployed in the Persian Gulf and another 60,000 troops are expected to arrive in the coming weeks, a U.S. official said Tuesday on condition of anonymity.

U.N. weapons inspectors returned Wednesday to sites around Baghdad where they have been destroying banned missiles and casting chambers.

The U.N. inspectors have crushed 19 Al Samoud 2 missiles since March 1. Iraq is believed to have had about 100 such missiles.

In Israel, officials have stressed that the country is better prepared than it was in 1991.

Israel now has the Arrow, the world's first fully deployed anti-missile system designed to intercept incoming missiles high in the stratosphere and far from their targets.

Israel and the United States have spent more than $2 billion to develop the Arrow.

Israel has also finished deploying several batteries of shorter-range Patriot missiles, which were largely ineffectual against Scuds in the 1991 Gulf War.