Moscow: At least 35 people were killed in an explosion that created a huge fire ball at a fuel station in Russia's remote Caucasus republic of Dagestan, spurring condolences from President Vladimir Putin.
Images distributed by the emergencies ministry showed burnt-out cars silhouetted by the massive blaze and rescue workers in helmets attempting to put out the fire and clear rubble.
Government ministries said 35 people had died and 80 had been injured.
The Kremlin issued a statement saying: "President Putin expresses his most sincere condolences to the families and friends of the victims of the tragedy in Dagestan and wishes a speedy recovery to the victims."
The explosion in the city of Makhachkala happened at a fuel station after a fire broke out, the regional branch of the Investigative Committee, which probes major incidents, announced on social media.
"A fire occurred during car maintenance work, followed by a bang, as a result of which people were injured and died," the committee said, adding that nearby buildings and cars were damaged.
A criminal case has been opened to establish the circumstances leading up to the fire, it added.
'Couldn't see anything'
State-run news agencies TASS and Ria Novosti reported that the fire had been extinguished, citing the ministry.
Makhachkala, a city of over 600,000 on the Caspian Sea, is the capital of Dagestan, a Russian republic bordering Chechnya.
The blast was heard shortly before 10:00 pm (1900 GMT) on Monday, Sergei Melikov, head of the Dagestan administration, announced on social media.
A witness quoted by Russian daily newspaper Izvestia said the fire started in an area where cars were parked and spread to the petrol station.
"After the explosion, everything fell on our heads. We couldn't see anything any more," said the witness, who was not named.
Video footage released by Russia's emergency situations ministry showed firefighters trying to extinguish huge flames near burnt-out vehicles, as rescue workers examined the rubble of a building with flashlights.
The fire had spread over an area of around 600 square metres (6,450 square feet), the ministry said, adding that 260 firefighters had been deployed ot the blaze.
A government Il-76 aircraft carrying medical equipment had been dispatched to Makhachkala to evacuate the seriously injured to Moscow, it added. Melikov said that evacuation operation had since been completed.
The Dagestan government declared August 15 a day of mourning.
"State flags will be flown at half mast throughout the country, and cultural institutions and TV channels will be asked to cancel entertainment events and programmes," Melikov said.