At least one person was killed when drones attacked a scientific institute in the Ukrainian capital Kyiv on Tuesday, AFP journalists and officials said.
Military rescuers removed a body covered with a black plastic sheet from the scene, AFP journalists saw.
Smoke rose from the white seven-storey building at the Institute for Superhard Materials in northwestern Kyiv, part of the National Academy of Science of Ukraine.
Soldiers at the scene pointed out a winged vehicle about a metre (three feet) long, smashed into two large pieces, that they said was a Russian drone.
A defence ministry intelligence official said at the scene that three people had died, but there was no other confirmation of the toll.
"During today’s air raid the armed forces of the Russian Federation used Orlan drones, one of which dropped a bomb, as a result of which the premises caught fire," the official, who asked not to be identified by name, told AFP.
"Later two more drones appeared and also tried drop bombs, they were downed. It used to be an industrial workshop here, a civilian institution. No military."
The body removed from the wreckage, which was in military uniform, was placed on a stretcher and covered in black plastic before being put into a van.
Wiring and circuitry could be seen inside the wreckage of the khaki-coloured drone, which lay in pieces on a road about 50 metres from the bombed building.
The attack came as Kyiv was under tight security because of a curfew that runs until Wednesday morning.
The capital was already reeling from a huge Russian missile strike on the Retroville shopping mall late Sunday that killed eight people.
Russia, which invaded Ukraine on February 24, said that the mall was used by the Ukrainian military to store rocket systems.
Moscow showed aerial footage of the mall attack and of what it said were Ukrainian military movements around the shopping centre several hours prior.