Russian missiles struck a crowded shopping centre in the central Ukrainian city of Kremenchuk on Monday, killing at least 16 people and wounding 59, the head of Ukraine's emergency services said early on Tuesday.
"As of now, we know of 16 dead and 59 wounded, 25 of them hospitalised. The information is being updated," Sergiy Kruk said on Telegram.
Mr Kruk said the main tasks were "rescue works, debris removal, and elimination of fires" after Monday's strike on the shopping centre.
"All response groups are working in intense mode," he said. "The work will go on around the clock.
"I would like to stress once again: do not neglect air alerts."
Dmytro Lunin, governor of the central Poltava region, earlier said that rescue workers would keep searching through the smouldering rubble, with more bodies expected to be found.
“It's an act of terrorism against civilians,” he said, suggesting there was no nearby military target at which Russia could have been aiming.
At one point, paramedics rushed into the building after rescuers called out “200", meaning they had found one or more bodies in the building.
Reporters were later pushed away from the scene as air raid sirens sounded again.
As night fell, rescuers used lights and generators to continue the search.
Worried family members, some close to tears, lined up at a hotel across the street from the mall where rescue workers had set up a base.
Kiril Zhebolovsky, 24, was looking for his friend Ruslan, 22, who worked at the Comfy electronics shop and had not been heard from since the blast.
“We sent him messages, called, but nothing,” Mr Zhebolovsky said.
He left his name and phone number with the rescue workers in case his friend was found.
The attack was earlier confirmed by Kyrylo Tymoshenko, deputy head of Ukraine’s presidential office, who said at least 20 people inside the mall had been wounded, with nine in a serious condition.
Ukrainian President Volodymyr Zelenskyy said more than 1,000 people were inside when the strike happened.
“The mall is on fire," Mr Zelenskyy wrote on Telegram. "Firefighters are trying to extinguish the fire. The number of victims is impossible to imagine.
“It's useless to hope for decency and humanity from Russia.”
Mr Tymoshenko said: “At the moment, we know about 20 wounded, nine of them are in a serious condition. It has already been confirmed that two people died. The rescue operation continues.”
City Mayor Vitaliy Meletskiy said the strike had caused deaths and injuries, but gave no figures.
Poltava Mayor Oleksandr Mamai posted a message on Telegram urging residents to seek shelter.
“Poltava residents. Explosions are heard in the city,” Mr Mamai wrote. “Stay in the shelters. Let's find out the details.”
Roman Hryshchuk, a Ukrainian MP, shared a video on Twitter appearing to show the aftermath of the shopping mall attack.
In the video, the building is engulfed in flames as firefighters try to rescue victims. People wearing military fatigues can also be seen.
“If this is not a terrorist attack, then what?” Mr Hryshchuk wrote on Twitter. “If Russia is not a terrorist country, then who are they?”
Inna Sovsun, another Ukrainian MP, tweeted her disgust over the “senseless attack by a terrorist state” and repeated calls for the West to supply more weapons to Ukraine and increase sanctions on Russia.
Kremenchuk, an industrial city of 217,000 people, is home to Ukraine’s largest oil refinery.
Since invading Ukraine on February 24, Russia has repeatedly attacked the refinery, which is 150 kilometres west of Dnipro.
The combined heating and power plant has been damaged to the extent that operations will not be restored before winter, reported Ukrinform, Ukraine's national news agency.
Ukraine conflict — in pictures
