WASHINGTON (AP) _ Five of the 57 additional U.S. aircraft sent to Europe last week in preparation for possible NATO air strikes on Serbia are being sent back to their home base in Washington state.

Five EA-6B Prowler electronic warfare planes will return from Europe to Whidbey Island Naval Air Station, the Pentagon said Friday. Five other Prowlers and the other fighters, bombers and air refueling planes sent as part of the buildup of U.S. airpower in Europe last week will stay for the time being.

``The repositioning of these air assets will have no impact on U.S. ability to support NATO air power requirements for Kosovo, should it become necessary,'' the Pentagon said in a written statement.

More than 240 American aircraft remain on alert in Europe for possible air strikes.