There were no immediate reports of foul play or of a connection to the war in Ukraine.
Russian state media said a fire at a nearby building Monday evening caused an explosion at the gas station in Makhachkala, the capital of the Dagestan region, on the Caspian Sea and near the foothills of the Caucasus Mountains. Another 63 people were hospitalized, local officials said.
Witnesses interviewed by Russian news media described an enormous blast. “I was at home, lying on the couch,” one woman said in a video interview circulated by Tass, a state-run news agency. “I don’t know how I ended up on the floor.”
The Kremlin published a brief message of condolence from President Vladimir Putin, and Dagestan Gov. Sergei Melikov, declared a day of mourning and promised to pay 1 million rubles (about $10,000) to each of the families of the dead.
Dagestan is one of the poorest parts of Russia’s majority-Muslim Northern Caucasus region. It was a refuge for Islamist insurgents in past decades, but Putin has pushed for an economic revitalization of Dagestan and championed it as a destination for domestic tourism.
During a visit to Dagestan in June, Putin walked onto a city square and, in a rare move for a president who still demands that many of those who meet with him quarantine first, greeted a crowd that was screaming with delight.
Dagestan has been the site of occasional protests, but there was no immediate indication that the gas station fire would exacerbate tensions. After Putin declared a draft for his invasion of Ukraine last fall, protesters in Dagestan blocked a federal highway.
On Sunday, more than 100 residents blocked a road in Dagestan to protest a prolonged disruption of the water supply to their homes, local authorities said.
This article originally appeared in The New York Times.