A mass drone attack struck several districts of the Ukrainian capital Kyiv early on Tuesday, damaging an apartment building and injuring up to 11 people, city officials said. Mayor Vitali Klitschko said swarms of drones continued to move towards the capital and warned of a danger of Russian missiles being deployed.

KYIV, Ukraine (AP) — A combined Russian and missile attack in Kyiv overnight Tuesday left at least 20 people wounded, according to Ukrainian officials.

Moscow’s drone strikes have grown exponentially thanks in part to a deal with Iran to produce its Shahed drones on Russian soil.