Firefighting helicopters are trying to put out a spectacular blaze atop an under-construction Moscow skyscraper, planned to be Europe's tallest building.
Orange flames were leaping about 250 metres in the night sky, visible to much of the city.
No injuries have been reported at the fire in the eastern tower of the Federation Tower complex, part of a massive development along the Moscow River about 1.5 miles west of the Kremlin.
The cause of the fire was not immediately known.
The tower, when completed, is to be 360 metres tall.