Israel has been continually running tests and simulations on it's Arrow anti-ballistic missile (ABM) system. Last month, they successfully conducted a test combat launch, with four of the six missiles on a launcher being fired in rapid succession. Since then, the equipment has been kept on alert, ready for instant use, for long periods. In addition, the Arrow early warning system has been electronically linked with the radars and communications of local Patriot surface to air missile units, U.S. warships offshore equipped with Aegis anti-aircraft systems modified to deal with ballistic missiles and early warning satellites. However, on March 23rd, while journalists were being given a tour of the Arrow command center, a siren went announcing an incoming missile. Ten minutes it was announced that it was a false alarm, the first one Arrow had experienced. An investigation continues into what caused the problem, as bad information may have come from any of the systems Arrow is linked with.