Moscow/Kyiv, July 2 -- Russia launched one of its largest air assaults in recent months on the Ukrainian capital Kyiv overnight, killing at least 18 people and injuring more than 80, Ukrainian officials said on Thursday, as waves of drones and missiles struck residential districts and other civilian infrastructure across the city.

Kyiv Mayor Vitaliy Klitschko described it as the "most massive attack" on the capital and declared Friday a day of mourning. He said around 90 people had been injured.

Although previous Russian attacks have killed more people or involved a greater number of weapons, the latest barrage struck locations across a wide area of the city.

"Kyiv is under attack from ballistic missiles and UAVs," Klitschko wrote on Tel...