Four people were killed in a Russian airstrike in Kyiv overnight, local officials said.
The city's mayor, Vitali Klitschko, said that air defenses were operating around the Ukrainian capital.
He added that windows were shattered in the Shevchenkivsky district, including a metro station, and a fire broke out in a non-residential building. It is not clear what was targeted.
The authorities warned of the threat of ballistic missiles and urged residents to go to shelters.
