Russian forces attacked a DIY shop in the Ukrainian city of Kharkiv on Saturday, killing at least two people and wounding many.
Local authorities said the attack sparked a large fire which firefighters were working to extinguish.
Kharkiv region governor Oleg Sinyekhbov said in the Telegram messaging app that two guided bombs had hit a DIY shop in a residential area of ​​the city.
In addition to the two confirmed dead, 24 people were injured, he said.
Kharkiv Mayor Igor Terekhov said many people were missing but did not immediately give a figure.
Up to 200 people may have been in the hypermarket at the time of the attack.
“The attack was aimed at a shopping centre where many people were present and is clearly a terrorist attack,” Terekhov said.
Video footage showed a huge plume of black smoke rising into the sky from the scene and fire engines and rescue teams heading to the scene.
Kharkiv is Ukraine's second-largest city and has been the target of Russian attacks for weeks.
Witnesses described scenes of panic at the shopping centre.
“I was at work and we heard the first explosion and fell to the ground with my colleagues. There was a second explosion and we were covered in rubble. Then we started crawling to higher ground,” Dmytro Syrotenko told Reuters.
He said he, several colleagues and shoppers were carried to safety by rescue workers.
Shortly after the attack, Ukrainian President Volodymyr Zelenskiy renewed his call for strengthening air defenses to protect the city of about 1.3 million people.
Moscow denies deliberately targeting civilians but its 27-month-long all-out invasion of Ukraine has left thousands dead and wounded.