Kyiv Mayor Vitali Klitschko said on Telegram that multiple explosions had taken place in the central Shevchenkivskiy district of the city at around 6:30 a.m. local time (0330 UTC) on Sunday.
"Ambulance crews and rescuers dispatched to the scene. Residents are being rescued and evacuated from two buildings," he said.
Klitschko later said two people were hospitalized and rescue efforts were ongoing as people were trapped under the rubble.
Emmanuelle Chaze, DW's correspondent in Kyiv, said there had been at least four explosions.
The AFP news agency reported that a residential complex near the center of the city had been hit, causing a fire and cloud of grey smoke.
There was no immediate information on casualties.
G7 summit to start in Germany
Germany is hosting the G7 summit from Sunday to Tuesday at the Elmau luxury resort in the Bavarian Alps.
World leaders began arriving on Saturday, including US President Joe Biden. As well as attending the summit, Biden is due to meet for bilateral talks with German Chancellor Olaf Scholz.
Scholz has said it is important that the summit send a signal of united support for Ukraine.
Proposals to jointly increase pressure on Russia, collective military and humanitarian support for Ukraine, and the impact of the conflict in driving energy and food prices sharply higher will be focal points at the summit.
