At least four people are believed to have been killed, and at least 80 injured. According to the Ukrainian authorities, dozens of residential buildings, several schools and a water supply facility were hit, and a market was burnt down.

13-year-old Vanya, whose Kyiv apartment was struck in the attack, escaped unharmed. “I just really hope my neighbours and friends are alive," he said to UN Children’s Fund (UNICEF) staff on the scene.

UNICEF described the massive, sustained attack as a “terrifying night for children and families”.

Woken by ‘terrifying sounds of war’

Matthias Schmale, the senior UN official in Ukraine, said that he and his colleagues had, like all residents of Kyiv, once again been woken up in the middle of the night by the “terrifying loud sounds of war”.

The strike, noted Mr. Schmale, lasted around seven hours, and falling debris sparked fires across the city. “Civilians live with immense risks as a result of this relentless violence,” the Resident and Humanitarian Coordinator declared. “The widespread pattern of civilian harm must stop.”

WHO offices hit

The Kyiv offices of the World Health Organization (WHO) were among the buildings hit in the overnight attack.

WHO chief Tedros Adhanom Ghebreyesus said in a social media post that debris from one of the strikes damaged windows on the third floor of a building that houses several UN agencies. No staff members were hurt.

Tedros called for a halt to attacks on health facilities and civilians and reiterated WHO calls for a ceasefire. “Peace,” he said, “is the best medicine.”