A 45-story building in the Chechen capital is burning.
Pictures show the fire that started on the fourth and fifth floors of the tallest building in the Grozny-City complex has spread throughout most of the building.
Russian news agency ITAR-TASS said the second through 40th floors were engulfed by fire.
Kantemir Davydov from the regional branch of the Emergency Situations Ministry said floors 30 through 40 were "engulfed" by flames and the heat from the fire was blowing out the windows on those upper floors.
Firefighting vehicles reportedly rushed to the scene but apparently were insufficient to battle the inferno and the latest reports said helicopters were flying to join in the attempt to extinguish the blaze.
Russian Deputy Emergency Situations Minister Aleksandr Chupriyan explained there were serious complications with putting out the fire on the top floors of the building.
"There is no automatic [fire-extinguishing system] installed inside that building yet; it is not completed. Besides, this new building does not yet have proper water supply," Chupriyan said.
"So, in accordance with the laws of physics, fire engines can only reach the 25th or 27th floor, at best, and the rest of the building remains uncovered."
Local authorities said the building was successfully evacuated and that no one was injured.
Images broadcast by Russian television stations showed much of the building engulfed in flames with large pieces of debris falling to the ground.
Reports said nearly 300 firefighters and 68 firefighting vehicles were participating in fighting the fire.
The building on fire was identified as the Olimp Hotel, the tallest building in Russia outside the Moscow area.
Russia's Emergency Situations Ministry has started an investigation into the cause of the blaze.
With reporting by ITAR-TASS and Interfax