Several people are missing and two men jumped to their deaths after an eight-storey office building near the Russian capital Moscow erupted in flames on Monday, authorities said.
The fire took hold in the town of Fryazino and video showed smoke and flames billowing out of at least three of the building's top floors, with a group of four people seen huddling around a broken window trying to escape.
The building was engulfed in black smoke and flames roared up its walls.
Some people were trapped on the top floors but were unable to escape.
"Two men jumped out of the window while trying to escape. Unfortunately, they died," Moscow regional Governor Andrei Vorobyov said.
"The fate of the two women who were on the eighth floor is being clarified."
About 30 companies rented space in the office block, two of which had employees working there at the time of the fire, Mr Vorobyov said.
"There were also oxygen cylinders in the building, which triggered explosions," he said. "This led to the collapse of the floor slabs."
The blaze spread to about 5,000 square metres before being contained, emergency services said.
Deadly fires are common in Russia, which has for years suffered from lax safety standards and struggled to modernise older buildings with alarms and firefighting equipment.
A criminal case has been opened and investigators are establishing the circumstances of the fire, Mr Vorobyov said.
