Ukrainian drones struck the Republic of Tatarstan overnight, hitting industrial facilities and at least one apartment building, regional head Rustam Minnikhanov said. The republic’s prime minister traveled to the scene, he added.

Minnikhanov did not identify the targeted facilities or their locations. The plants are “promptly addressing the aftermath” of the strikes, he said, and “production processes have not been halted.”

Residents of the building hit by one of the drones were evacuated. Three people were injured and are receiving medical care. Minnikhanov again declined to say where the building is located. The region’s Health Ministry later reported four people injured.

The Russian security services-linked Telegram channel Baza claims the strike hit the city of Nizhnekamsk, where a drone slammed into the upper floors of a 12-story building and started a fire.

The city’s mayor, Radmir Belyaev, addressed only the threat of a drone attack, not its consequences. With an air raid alert in effect in Nizhnekamsk, all public events planned for June 12 — Russia Day — were canceled “to ensure public safety.”

Belyayev also asked residents to “follow only official communications,” not to trust unverified information, and not to spread rumors.

The independent Telegram channel Astra reported in preliminary findings that several drones were shot down over Nizhnekamsk and that there were hits in an industrial zone. Eyewitnesses said there were no air raid warnings.

The Ukrainian monitoring Telegram channel Exilenova+ published photographs and video of what it says are the aftermath of the attack on Nizhnekamsk. Exilenova+ claims that the fire following the drone strike broke out not only in the residential building but also at the Nizhnekamskneftekhim oil refinery, a Sibur subsidiary.

Another Ukrainian channel, Supernova+, reports that a fire broke out at the TANECO refinery, which belongs to Tatneft.

In total, the Defense Ministry said, 231 Ukrainian drones were shot down overnight on June 12 over 15 Russian regions, occupied Crimea, and the Sea of Azov.

In recent months, Ukraine has increasingly struck Russian oil facilities and other infrastructure. Against this backdrop, a fuel crisis has emerged in more than 20 regions of the country, as well as in occupied Crimea.