A major fire has erupted at a top-secret Russian defense research plant leaving one dead and 30 injured.

Four military scientists were reportedly forced to jump out of windows of the burning Second Central Research Institute for the Ministry of Defence of the Russian Federation.

Those injured are currently receiving medical attention, according to Global Happenings.

Initial reports said the fire started on the second floor of the top-secret research institute in Tver which develops new space and weapons systems at around 11.08am, local time.

Flames quickly spread throughout the building due to the wooden flooring, reports said.

The cause was not clear but there were reports of “poisonous bluish-black smoke”.

Footage from SOTA Vision TV shows thick clouds of smoke protruding from the building with huge flames emerging from windows on the upper floors as a number of people watch from a distance.

It was unclear if there were chemical releases before the fire or as a result of the raging inferno which spanned 1,000 square metres.

Eyewitnesses report that because of the smoke, people who were in the room could not evacuate and had to jump from the windows.

They also claim that the injured people were seen covered in blood and cuts from their escape.

Emergency services are said to be facing complications caused by strong winds, which reach 12 m/s as the wind is carrying smoke towards the city.

Traffic is mounting up on the Afanasy Nikitin embankment, where the building is located. Bus routes have been rerouted.

The Armed Forces of Ukraine claim the institute was engaged in the development of air defence weapons and produced navigation instruments, control systems, guidance and orientation of ground, air and space-based vehicles.