A Russian attack with Iran-made drones early Monday left two people dead and three more wounded in the western Ukraine city of Khmelnytskyi, the mayor said.

Mayor Oleksandr Symchyshyn said in separate messages on social media that two rescue workers had died in hospital following the attack with more than a dozen unmanned aerial vehicles.

“Unfortunately, we have another hospital death. Doctors failed to save the life of another hero – a rescuer,” he said in the second statement after earlier reporting the first death.

The Ukrainian armed forces said it had shot down 11 out of 14 “Shaded” drones deployed by Moscow’s forces overnight.

Nine were downed over the capital Kyiv, the head of the city’s military administration said, and there were no reported casualties or damage to infrastructure.

The official, Sergiy Popko, said Russian forces were trying “to exhaust our air defences,” and said the attack had come in two separate waves.

Russia has been launching missile and drone attacks on Ukraine’s critical infrastructure since October, spurring Kyiv to bolster its air defence systems with Western help.

The attacks have plunged millions in the cold and dark in the middle of winter.