Ukrainian leader Volodymyr Zelensky said Monday that the number of wounded in a Russian strike on the city of Sumy Monday rose to almost 90 people, including 17 children.
The strike hit the day Russia is holding talks with the US in Saudi Arabia on a potential ceasefire.
Ukrainian officials earlier said the strike hit residential buildings and educational facilities in the north-eastern city that lies close to the Russian border.
"There are a lot of wounded -- as of now, we know about almost 90 people, including 17 children," Zelensky said in his daily evening address on social media, adding that rescue operations were still ongoing
He said that a "school and residential buildings are at the epicentre" of the strike.
"Fortunately, the children at the school were in a shelter," he said.
"Every day like this, all the nights with Russian missiles and drones against our country, every day of the war means losses, pain, and destruction that Ukraine never wanted," the wartime leader added.
Despite US President Donald Trump's push for a rapid end to the conflict, attacks have continued unabated in Ukraine, including on the region of Sumy that borders Russia.
The attack damaged apartments and an educational facility, prosecutors said.
The city's acting mayor Artem Kobzar earlier said a hospital had been affected.
The regional administration published videos showing damaged high-rise residential buildings, with many balconies blackened and smoke billowing out.
It also showed debris on a basketball court and firefighters working to put out a blaze.
Russia briefly occupied parts of Sumy at the start of its full-scale invasion in 2022.
It lies across the region of Kursk, where Ukrainian troops led a shock offensive late August before being mostly pushed back.
