Russian forces attacked downtown Kharkiv on Dec. 30, injuring 20 people, Kharkiv Mayor Ihor Terekhov reported.
Among those injured are two boys aged 14 and 16.
The city was reportedly attacked with at least six missiles, one of which struck a residential building, causing a fire.
The attack comes a day after Russia unleashed the largest air attack on Ukraine.
The Dec. 30 attack on Kharkiv damaged several multi-story residential buildings, a shop, and public spaces, Kharkiv Oblast Governor Oleh Syniehubov reported.
“Solely civilian infrastructure was attacked,” Syniehubov said, adding that emergency services are on the scene.
The attack also damaged the Kharkiv Palace, a five-star hotel in the city's center, injuring a woman and a foreign journalist.
Several hours before the Kharkiv attack, Russian authorities claimed a Ukrainian attack on Russia's Belgorod Oblast, including the regional capital.
The Russian Emergency Situations Ministry claimed that 14 people were killed, including two children. Some 108 people, including 15 children, were allegedly injured. The Kyiv Independent could not verify the claims.
Ukraine has not claimed responsibility. Kyiv generally does not comment on reports of attacks and explosions on Russian soil.