Several explosions took place early on Sunday in the Shevchenkivskiy district of the Ukrainian capital Kyiv, the city's mayor Vitali Klitschko said on the Telegram messaging app.
There was no immediate information on the cause of the explosions or casualties.
"Ambulance crews and rescuers dispatched to the scene. More detailed information - later," Klitschko said.
"Residents are being rescued and evacuated from two buildings."
The historic district, one of Kyiv's central, is home to a cluster of universities, restaurants and art galleries.
Russia invaded Ukraine on February 24 but abandoned an early advance on Kyiv in the face of fierce resistance bolstered by Western arms.
Since then Moscow and its proxies have focused on the south and Donbas, an eastern territory made up of Luhansk and its neighbour Donetsk, deploying overwhelming artillery in some of the heaviest ground fighting in Europe since World War Two
