Iraq said that its aircraft are flying in the "no-fly" zones patrolled by U.S. and British warplanes and that its antiaircraft batteries remain ready to fire on allied planes. U.S. officials would not say whether Iraqi aircraft encountered in the zones would be shot down. Iraq's move came a day after U.S. planes fired on an Iraqi antiaircraft position in the north, killing four Iraqi soldiers. Washington said the planes attacked after Iraq shot missiles at aircraft patrolling in the northern of two "no-fly" zones set up after the 1991 Persian Gulf War. The latest announcement by Iraq appeared aimed at building support among Arabs who protested mid-December airstrikes by Washington and London.