Russian airstrike hits busy shopping mall in central Ukraine, sparking fears of mass casualties

(CNN)A Russian airstrike struck a bustling shopping mall in Kremenchuk, central Ukraine on Monday, setting the building ablaze and prompting concerns of mass casualties.

Ukrainian President Volodymyr Zelensky said up to 1,000 people were in the mall when it was hit by missiles, adding: "The number of victims is impossible to imagine."

Later on Monday, the head of the Poltava region military administration, Dmytro Lunin, said 10 people had died in the attack. Another person later died at hospital, taking the death toll to 11, Ukraine's State Emergency Services said.

At least 58 people were injured, they said.

Video from the scene showed heavy smoke billowing from the building, which was engulfed by fire. The mall measures about one hectare -- roughly the size of two football fields -- and the strike occurred around 4 p.m. local time, Solohub said.

"We don't know how many more people might be under the rubble," said Volodymyr Solohub, a regional official in the Poltava Oblast local administration.

The attack targeted a site in central Ukraine far away from the epicenter of Russia's war, which has recently been focused in the east of the country.

It came as G7 leaders met at a summit in Germany that was mostly geared toward coordinating the Western response to Russia's invasion.

British Prime Minister Boris Johnson said from that meeting that the attack showed the "depths of cruelty and barbarism" of Russian President Vladimir Putin, the UK's PA news agency reported.

"This appalling attack has shown once again the depths of cruelty and barbarism to which the Russian leader will sink," Johnson said, according to PA.

And Ukraine's Foreign Minister, Dmitro Kuleba, said on Twitter: "Russia is a disgrace to humanity and it must face consequences. The response should be more heavy arms for Ukraine, more sanctions on Russia, and more businesses leaving Russia."

Those issues were on the table at the summit in Germany. The G7 vowed to continue providing support for Ukraine "for as long as it takes" in a joint statement, and European Commission President Ursula von der Leyen told CNN on Monday that she would not "bet on Russia" winning the war.