The Japan Map Center has found 29 negatives of aerial photographs of Nagasaki taken by the U.S. military a day after it dropped an atomic bomb on the city in 1945, in a discovery expected to help reveal the immediate effects of the attack.

The pictures, taken by a U.S. reconnaissance plane flying over the devastated city Aug. 10, 1945, were found at the U.S. National Archives and Records Administration.

They are believed to be the first aerial photos of Nagasaki taken a day after the bombing to be made public. The oldest such photos, taken Aug. 12, are currently kept by the Nagasaki Atomic Bomb Museum, the map company said.

Last December, Japan Map Center officials found documents showing the flight route of the reconnaissance plane and black-and-white negatives at a branch of the U.S. National Archives and Records Administration in Maryland, according to Kunio Nonomura, head of the center.

The officials brought back digitized copies of the negatives to Japan.

The map firm will publish some of the photos in an extra edition of its monthly magazine issued Aug. 1.