Kharkiv Regional Governor Oleh Synehubov, writing on the Telegram messaging app, said two women were seriously injured and residences had been damaged. He said two Russian missiles had hit the city centre.

"These strikes were in the city centre," Kharkiv Mayor Ihor Terekhov wrote on Telegram. "Precisely where there is no military infrastructure and precisely where there are in fact residences."

Terekhov told national television that rescue teams were going through damaged buildings to see if more residents had been injured.

Kharkiv, in Ukraine's northeast, has been a frequent target of attacks, but in the space of the nearly two-year-old conflict, the city has not fallen into Russian hands. Russian missiles hit a hotel in the city last week, injuring 11 people.

(Reporting by Ron Popeski and Maria Starkova; Editing by Leslie Adler and David Gregorio)