Families in Ukrainian cities are taking refuge from massive swarms of Russian drones, as Moscow steps up its airborne assault with attacks designed to undermine Ukrainian morale.

One of the hardest-hit areas was the city of Kharkiv in northeastern Ukraine, where 17 attack drones struck two residential districts, Mayor Ihor Terekhov said. Emergency crews, municipal workers and volunteers worked through the night to extinguish fires, rescue residents from burning homes, and restore gas, electricity and water services.