Kyiv’s mayor made an unprecedented call to residents to seek temporary refuge outside the Ukrainian capital after a Russian aerial barrage triggered widespread shortages amid frigid temperatures.

Vitali Klitschko made the plea after large swathes of the city were hit by disruptions to heating, water and power supplies — a hardship for residents already contending with temperatures set to drop to as low as -17C (1F) in the coming days.

“I am appealing to residents of the capital who have the opportunity to temporarily leave the city for areas where there are alternative sources of power and heating to do so,” Klitschko said early Friday on Telegram.

The overnight strike — involving 36 missiles and some 250 drones — killed at least four people in Kyiv and left large sections of the city without heating and water access overnight. Half of Kyiv’s apartment blocks, a total of almost 6,000 buildings, remained without heating, Klitschko said.

One of Europe’s largest cities with a prewar population of between 3 and 4 million, Kyiv has been a regular target of strikes throughout Russia’s four-year war. While the attack wasn’t the first time it experienced significant outages, weather conditions compounded the suffering.

Facilities including hospitals have been connected to mobile heating plants, Klitschko said. With services operating in emergency mode, weather conditions were forecast to be difficult into the coming days, he said.

“The combined attack on Kyiv last night was the most painful for the capital’s critical infrastructure,” Klitschko said.

— With assistance from Olesia Safronova