At least two explosions were heard in Kyiv, with Mayor Vitali Klitschko saying that Russian troops fired on the capital.
The Kyiv mayor said on Telegram that there had been "two hits in the Shevchenkovsky district."
Klitschko said authorities are still uncovering information related to casualties from the attack.
The explosions occurred shortly after UN Secretary-General Antonio Guterres held a press conference with Ukrainian President Volodymyr Zelenskyy in the city.
"Today, immediately after the end of our talks in Kyiv, Russian missiles flew in the city. Five rockets," Zelenskyy said. "This says a lot... about the Russian leadership's efforts to humiliate the UN and everything that the organization represents."
Ukrainian Foreign Minister Dmytro Kuleba said Russia struck the capital with "cruise missiles" and labeled the attack a "heinous act of barbarism."
Ukrainian presidential adviser Mykhailo Podolyak called for Russia to be removed from the UN Security Council following the attack.
Guterres says UN Security Council failed to prevent Ukraine war
UN Secretary-General Antonio Guterres said the UN Security Council failed in its efforts to prevent Russia's war on Ukraine.
"Let me be very clear: the Security Council failed to do everything in its power to prevent and end this war. And this is the source of great disappointment, frustration and anger," Guterres said at a press conference with Ukrainian leader Volodymyr Zelenskyy.
Guterres and Zelenskyy also discussed ongoing attempts to evacuate the Azovstal steel plant in the southern port city of Mariupol. Ukrainian fighters and civilians are currently trapped in the plant amid a Russian blockade.
"At the present moment I can only tell you we are doing everything we can to make it happen," Guterres said.
"I trust and believe — just as many relatives of those who are blocked in Azovstal (steel plant) do — that the Secretary-General will have a successful result," Zelenskyy said.
