Two people were killed and twelve were injured on Sunday in a Ukrainian drone attack on the city of Nizhnekamsk in Tatarstan, according to the office of regional president Rustam Minnikhanov.
The city is home to oil refineries and important factories.
Ukraine also said on Sunday that it had attacked an oil refinery in Slavyansk-na-Kubani in Russia's Krasnodar region.
The Russian Ministry of Defence said 389 Ukrainian drones were shot down overnight into Sunday, including over Tatarstan.
At least nine people were injured in a nighttime Russian attack on Odesa, Ukraine, according to the head of the regional military administration, Serhiy Lysak.
