A Russian fighter plane crashed into a residential building in the southern Russian city of Yeysk on Monday, engulfing apartments in flames, the regional governor said, Reuters reports.
Footage showed a large fireball erupting from a multi-storey building. Russian news agencies said the pilots had ejected.
Governor Veniamin Kondratyev said the plane was a Sukhoi Su-34, a supersonic medium-range fighter-bomber.
RIA news agency said it crashed during a training flight from a military airfield. TASS said the crash was caused by an engine fire.
Russia's state Investigative Committee, which deals with serious crimes, said it had opened a criminal case and sent investigators to the scene. It did not say what evidence pointed to potential foul play.
Interfax quoted the Kremlin as saying President Vladimir Putin had been informed, and had ordered all necessary help to be provided to victims. The health and emergencies ministers were ordered to fly to the region, it said.
"Emergency services are already working on the spot - all regional fire and rescue garrisons are engaged in extinguishing the fire," Kondratyev, governor of the Krasnodar region which includes Yeysk, wrote on Telegram.
He said the fire had broken out in a nine-storey building. "The fire engulfed several floors at once. Seventeen apartments were preliminarily damaged," Kondratyev said. "Information about the dead and injured is being clarified. Ambulance crews are on the scene."
Yeysk is separated from occupied Russian territory in southern Ukraine by a narrow stretch of the Sea of Azov.
The incident comes nearly eight months after Russia sent troops into Ukraine.
