Ukrainian President Volodymyr Zelensky accused Russia on Wednesday of carrying out an airstrike on a hospital in the southern port city of Mariupol in which he said children were among people "under the wreckage".
Mariupol's city council said the hospital had been destroyed.
Seventeen people were wounded in the attack, including women in labour, said regional governor Pavlo Kyrylenko.
Russia and the Syrian regime have been found to target health facilities in airstrikes in opposition areas of Syria, with dozens of clinics and hospitals destroyed in the bombing, including maternity wards.
A new ceasefire was announced by Moscow on Wednesday in order to allow civilians to flee besieged cities, such as the city of Mariupol.
However, there have been only limited reports of progress in relation to evacuations.