Blasts were heard in Ukrainian capital of Kyiv and in the major city of Kharkiv on Monday morning, Ukraine's State Service of Special Communications and Information Protection said.
Kyiv had been quiet for a few hours prior to that, it said in a brief statement on the Telegram messaging app.
In a separate statement, the agency said a residential building in the city of Chernihiv in northern Ukraine was on fire after being struck by a missile.
Another northern Ukrainian city, Zhytomyr, was hit by missiles overnight, Ukrainian Ground Forces command said on Facebook.

Isaias weakens to post-tropical cyclone after Florida landfall, NHC says
India detains youth protest leader to defuse rally against election chief
Magnitude 7.7 quake shakes Panama, canal operations normal
US imposes sanctions on International Criminal Court
Three Saudi nationals killed in attacks on Riyadh airport, aviation authority says
