At least 10 people were wounded when the centre of Ukraine's second city, Kharkiv, was hit by Russian rocket fire on Friday, local officials said, while the president's top aide said the attacks were revenge for Ukrainian success on the battlefield.
Rockets hit a children's arts centre and a school, as well as private homes, Kharkiv's Mayor Ihor Terekhov said.
Regional Governor Oleh Synehubov said 14 people, including three children, had been wounded by the rockets, which he said were fired from Uragan MLRS systems.
Ukraine's presidential chief of staff Andriy Yermak said the attack was revenge for the success of Ukraine's armed forces, an apparent reference to a recent counter-attack in nearby areas which Ukraine says led to the recapture of over 20 settlements.
"For every success of Ukraine's armed forces, for every victory, Russians... answer with strikes on innocent people," Yermak wrote on Telegram, confirming that children were among the wounded.
"Russia is a terrorist state... you will answer (for this), and you almost certainly won't be able to hide anywhere," he wrote.
It was not immediately possible for Reuters to verify the reports. Russia denies targeting civilians.
Earlier on Friday, Synehubov warned residents that Russia had increased strikes on the province in response to Ukraine's assault.
Synehubov said four people had been killed by Russian shelling in the region on Thursday, including two in the city of Kharkiv.
"The intensification of the occupiers (shelling) is connected primarily to the successes of Ukraine's armed forces, which are currently liberating the territory of the region," he wrote on Telegram.
(Reporting by Max Hunder; editing by John Stonestreet, Philippa Fletcher and Jonathan Oatis)
