Israel's military on Monday instructed Israelis to acquire all the equipment they need to protect themselves in case of an Iraqi attack.
A statement issued by the Home Front Command said Israelis "should complete their preparations and acquisition of insulation materials and other equipment for sealed spaces."
The statement stopped short of telling Israelis to prepare a sealed room in their house and said people "must not open their gas mask kits without specific instructions" to do so.
Defense Minister Shaul Mofaz said earlier Monday that final instructions about preparing sealed rooms will be given when Israel learns that a U.S.-led offensive against Saddam Hussein is about to begin.
"As of now, we do not have information about the timing of the beginning of the battle," Mofaz said as he answered questions on an Internet chat on the Maariv newspaper's Web site.
The conflict "will begin soon," Mofaz said. "When we know the date, we will update the public."
Mofaz added that according to Israeli intelligence, Saddam does not have missiles deployed within range of Israel and the probability of an attack against Israel is low.
However, if Iraq strikes, he said, "Israel will know how to defend its citizens."
In a weekend television interview, Mofaz indicated Israel's response might include a counterattack.
Israel TV reported later Monday that the army would mobilize some reserve soldiers in anti-aircraft units and the Home Front Command. The military refused to comment on the report. Israel TV also said Israeli air force planes are on the runways and ready to move at a moment's notice.
The British and Japanese embassies on Monday urged their citizens to leave Israel, the West Bank and Gaza Strip because of the approaching battle.
The conflict claimed its first victims in Israel even before a shot was fired. A mother and her two teenage sons suffocated to death in their sealed room, police said Monday.
Jumping the gun on precautions, the family, Israeli Arabs from a village near Tel Aviv, sealed a bedroom and opened their gas mask kits, then went to sleep.
A heater in the next room apparently sucked the oxygen out of the room, which was sealed against letting air in but allowed oxygen to escape.
Around 5 a.m., the husband awoke and realized his wife, 37, and two of their children, ages 14 and 13, were not breathing, police said. Two other children, ages 4 and 3, survived.
Israelis were first issued gas masks and ordered citizens to seal rooms in their houses before the 1991 Gulf War, when the United States led a broad coalition of forces to expel Saddam's forces from Kuwait.
Making good on Saddam's threats to hit Israel in retaliation, Iraq fired 39 Scud missiles at Israel. Most landed in the Tel Aviv area, carrying conventional explosive warheads that caused damage but few casualties.