The Russian Historical Society published a report by the USSR Embassy in Japan on the consequences of the American atomic bombings of Hiroshima and Nagasaki. This document is kept in the Russian Foreign Policy Archive. The society's website claims that the report is being published for the first time.
A group of Soviet embassy workers visited Hiroshima and Nagasaki about a month after the bombings. They arrived in Hiroshima on September 14, 1945. “The railway station and the city were destroyed to such an extent that there was not even a place to hide from the rain. The stationmaster and his staff took shelter in a hastily built shed. The city is a scorched plain with towering 15-20 skeletons of reinforced concrete buildings,” the report says.
Embassy staff spoke with eyewitnesses to the bombing. One of them said that he “heard the sound of a burst and the flash of lightning from a distance of 50 kilometers.”
The workers of the Soviet embassy arrived in Nagasaki on September 16. Citing an eyewitness, they said that on the first day after the bombing, no rescue work was carried out in the city due to a strong fire. “There is a strong putrid smell in the area where the bomb fell: many corpses have not yet been removed from under the ruins and conflagration,” the report says.