Japan and the United States formally adopted new guidelines Thursday for low-altitude flight training by U.S. military aircraft in Japan that restricts practice on weekends and holidays.

This is the first time Tokyo and Washington have drawn up a written agreement on U.S. flight drills over Japanese soil, Foreign Ministry officials said.

A bilateral committee in charge of the issue has been in working-level talks for months, and the flight drill guidelines were approved Thursday to coincide with Defense Secretary William Cohen's visit here, the officials said.

According to the guidelines, U.S. forces in Japan will continuously review areas for low-level flight training to ensure maximum safety. Thus, U.S. military aircraft will avoid flights over nuclear power facilities and civil airports.

Over congested areas and other public buildings such as schools and hospitals, U.S. forces are to pay due attention when they fly over such areas, the guidelines say.

Prior to conducting training flights, including low-altitude flights, air crews will conduct thorough briefings to review standard operating procedures, according to the guidelines.

In consideration of the noise concerns of the Japanese public, U.S. forces will limit low-level flight training on weekends and Japanese holidays to only essential cases, the guidelines say.

For those living under the paths of the flights, however, the code of conduct may hardly ensure peace of mind, since much of what happens will depend on independent efforts from the U.S. side and because the legal ground for Japan to demand improvements is still weak.

During fiscal 1997, 33 cases of damage were reported to Japanese authorities, including some alleging that windows were shattered by U.S. military flights, the officials said.