Russia bombarded Ukraine on Monday, killing two people in the Kiev region, authorities said on the eve of a diplomatic summit in France.
A countrywide siren was issued just after midnight, while Ukraine's military said air defenses were operating in several places.
In the capital, a private medical facility caught fire as a result of the Russian strikes, killing one person and wounding three others, the State Emergency Service of Kiev said. It released images of rescuers removing people on stretchers from a gutted building.
Another pre-dawn attack on the neighboring city of Fastiv killed one man in his 70s, according to Kiev regional governor Mykola Kalashnyk.
The strikes caused power outages in the area, with backup systems activated to maintain water and heating supplies, the official said, as temperatures dropped to -8 degrees Celsius.
The attacks came on the eve of a meeting of European leaders in Paris as they seek a breakthrough on a peace plan Kiev says is "90 percent" ready.
To lay the groundwork, security advisers from 15 countries, including Britain, France and Germany as well as representatives from NATO and the European Union, gathered in Kiev over the weekend.
U.S. special envoy Steve Witkoff joined the talks virtually, a Ukrainian official told AFP, though the United States' large-scale military attack on Venezuela earlier in the day overshadowed proceedings.
Another preparatory meeting, between chiefs of staff, is scheduled for today.
Diplomatic efforts to end Europe's deadliest conflict since World War II have gained pace in recent weeks, though both Moscow and Kiev remain at odds over the key issue of territory in a post-war settlement.
