ISTANBUL

At least four people have been killed and 10 injured following Russian strikes on Ukraine's capital, Kyiv’s mayor said Friday.

"Four people died in the capital. 10 people were injured. 5 of them were hospitalized by doctors. The others were treated on the spot," Vitali Klitschko wrote on Telegram.

Russia has not yet responded to reports about the strike in Kharkiv, and independent verification is difficult.

Separately, Ukraine’s Air Force said that “a massive attack by enemy strike UAVs (unmanned aerial vehicles) on Kyiv is underway!”

It said “all of Ukraine” is under a “missile threat” and confirmed that Russian aircraft were airborne.