Editor's note: This is a developing story and is being updated.
The Okhmatdyt hospital, Ukraine's largest children's medical center, was hit during a Russian missile attack on July 8, President Volodymyr Zelensky reported.
"The hospital has been damaged by a Russian attack, people are under the rubble, the exact number of wounded and dead is currently unknown," Zelensky said.
"Everyone helps to clear out the debris: doctors, regular people," he added.
According to Kyiv Mayor Vitali Klitschko, patients of the children's hospital "are being evacuated to the municipal hospital of the city."
"It is a nightmare. This is another evidence of (Russia's) genocide, what Russians are doing to Ukraine and our city," he said.
"I cannot say for sure whether it was a missile or debris (that hit the hospital). But considering the scale of destruction, it's unlikely that it was a fragment from the debris," Deputy Head of the Presidential Office Oleksii Kuleba told the Kyiv Independent.
Kuleba added that more people may be under the rubble. The rescue operation is ongoing.
At least two people were killed, the State Emergency Service reported at around 1:30 p.m. local time. Klitschko later clarified that both killed were adults. One of them was a doctor.
At least 16 people were injured, including seven children. Fifteen victims were hospitalized, the mayor added.
"I don't understand how people can be such animals. Even animals don't do such things. They are not even animals," Alla Nesolionova, a doctor at the cardiology center at the Okhmatdyt hospital, told the Kyiv Independent.
"I don't know how these pilots can launch missiles. They know the targets. They know the coordinates."
"The only thing I want is that this will be back to them a million times worse. I want them to feel it on their own skin," she added.
Russia launched another attack against Kyiv later during the day, with debris damaging a maternity hospital, killing four people and injuring three.
Fifteen people were killed in the capital during the day, and at least 37 were injured, the Prosecutor General's Office said.
Apart from Kyiv, Dnipro, Kryvyi Rih, Sloviansk, Pokrovsk, and Kramatorsk also came under attack. Around 40 missiles of various types were launched against Ukraine, Zelensky said.
Read also: Explosions rock Kyiv, other cities in Russian Monday morning massive attack