An anti-missile missile under development by Israel and the United States missed its target Thursday in its latest test off the California coast, a spokesman said.
The Arrow missile failed to intercept an air-launched missile over the Pacific and both fell into the water, said Chris Taylor, spokesman for the U.S. Missile Defense Agency.
"The engineers don't yet know what happened," Taylor said.
It was the 13th Arrow intercept test and the eighth test of the complete weapon system. Officials have not said how many of the tests have been successful.
Last month, an Arrow hit a missile launched from a platform on the ocean range off Point Mugu.
The Arrow system is continuing to undergo development after first being deployed by Israel after the Gulf War, when Iraq fired 39 Scud missiles at that nation.
In Thursday's test the Arrow was trying to hit a short-range, air-launched target. Taylor described the target only as representative of a threat that Israel might encounter.
A C-17 aircraft dropped the target missile 360 miles west-northwest of San Nicolas Island, its booster ignited and it flew correctly, Taylor said. Radar picked up the target and the Arrow was launched from San Nicolas.
The intercept should have occurred at 10:10 a.m. PDT west-southwest of San Nicolas, which is about 70 miles southwest of the Los Angeles coastline.