MOSCOW, April 21. /TASS/. The number of people killed in a fire at the Central Research Institute of the Aerospace Defense Forces in the Russian city of Tver has risen to two, while one person is missing, an emergency source told TASS.

"Two people were killed, the fate of another one remains unknown, reports of his death are being verified. About 30 people suffered injuries. More than 30 were evacuated from the building," he said.

The building’s roof has collapsed.

According to earlier reports, some people suffered from smoke inhalation, while others received injuries after jumping out of windows to escape the fire.

The blaze, which started on the second floor and engulfed about 1,000 square meters, hasn’t been contained yet. According to preliminary reports, the fire was caused by a power grid failure.