Israel carried out its most ambitious test yet of the Arrow antimissile system today, firing several interceptors at simulated incoming rockets in what was described as a dress rehearsal for a possible attack by Iraq.

In nine previous launches, only one Arrow was fired each time. Israel Radio reported that today's test was successful, but Army Radio said the results were still being evaluated.

The test, reportedly conducted in the presence of U.S. experts, was seen as a signal to Iraqi leader Saddam Hussein that any missile strike could be thwarted by the high-tech system.

Israeli officials think Iraq may try to attack the Jewish state with Scud missiles in response to an anticipated U.S. military campaign against Hussein. During the 1991 Persian Gulf War, Iraq fired 39 Scud missiles with conventional warheads at Israel, causing damage but few casualties.

The launch at the Palmachim air force base south of Tel Aviv included the firing of four Arrow missiles in succession over the Mediterranean to intercept four computer-simulated targets, according to a statement by the Israeli Defense Ministry.

The Arrow is the most advanced missile defense system of its kind in the world, and a multiple test had not been performed before, said Yitzhak Ben-Israel, who used to oversee the Arrow project at the Defense Ministry. "We want to test the ability of the system to fire many missiles at once against a barrage of Scud missiles," Ben-Israel said on Army Radio. No actual target missiles were fired today.

In response to the Gulf War, Israel and the United States invested $2 billion in the Arrow project. The Arrow is designed to shoot down projectiles about 31 miles above ground.

The United States hopes that in beefing up Israel's defense, it will lower the probability of Israeli retaliation if Iraq attacks. Israeli officials have said its response would depend on the casualties and damage caused by an Iraqi strike.

An Israeli attack on Iraq could anger the Arab world and spark widespread opposition to a U.S. offensive in Iraq.

Israeli Arrow missile was one of four launched almost simultaneously from an air base south of Tel Aviv at four computer-simulated incoming rockets.