Russia attacked Kyiv with "kamikaze" drones on Monday morning, according to a top Ukrainian official, who repeated calls for Western allies to supply the country with more advanced air defense systems.

In a separate Telegram message, Kyiv Mayor Vitali Klitschko said the “drone attack” caused a “fire in a non-residential building.”

“Firefighters are working. Some residential buildings have been damaged. Medics are on the site,” Klitschko said.

At least three explosions were heard in the Ukrainian capital at around 6:45 a.m. local time on Monday as a result of apparent Russian strikes, according to CNN's team on the ground.