More than 800 drones were launched in waves designed to overwhelm Ukrainian air defences, according to news reports, and a Government building was hit in the capital Kyiv for the first time.

Ukrainian authorities reported that four had been killed, with 44 injured. Air-raid sirens continued for 11 hours straight across the capital and although a majority were shot down more than 50 drones and nine missiles hit their targets.

“Yet again, attacks impacted homes, a government building, a kindergarten and other civilian infrastructure in Kyiv and Chernihiv, Kharkiv, Kremenchuk, Kryvyi Rih, Odesa, Sumy region, Zaporizhzhia – leaving behind loss, destruction and grief,” said UN Humanitarian Coordinator for Ukraine, Matthias Schmale, in a post on social media.

The top aid official said that together with authorities, the UN and humanitarian partners had mobilised to provide urgent support to civilians and civilian areas where damage was sustained.

Civilians should never be a target

“Civilians and civilian infrastructure are protected under international humanitarian law – they are not a target,” he continued.

The UN Children’s Fund, UNICEF, said that the news of a baby being killed along with their young mother in an attack on an apartment building in Kyiv was “devastating”. At least one other child was injured during the attacks on Sumy.

“Ukraine endured another terrifying night of attacks that impacted multiple cities. More young lives brutally cut short,” the agency tweeted.

The attacks came following weeks of high profile diplomacy from Western allies of the Ukrainian Government to broker a lasting peace deal between Kyiv and Moscow.

President Volodymyr Zelenskyy said in a social media post following the attacks that “such killings now, when real diplomacy could have already begun long ago, are a deliberate crime and a prolongation of the war.”