The Minister of Internal Affairs of Ukraine is among 18 people who have died after a helicopter crashed by a nursery in a Kyiv suburb, authorities have said.
Images from the scene show huge flames and a plume of smoke going into the sky in Brovary, which is located northeast of the capital.
Minister Denys Monastyrskyi and First Deputy Minister Yevhen Yenin were among those killed in the incident, as well as three children.
President Volodymyr Zelenskyy said the officials were “true patriots of Ukraine”.
He added: “As of this minute, three children died. It is an indescribable pain.”
There has been no immediate information about what caused the helicopter to come down.
Kyiv regional governor Oleksiy Kuleba said 29 people were also hurt in the crash, including 15 children.
Footage from what Ukrainian police said was the scene showed flames across a wide area of the suburb where the aircraft came down.
Mr Kuleba added: “At the time of the tragedy, children and staff of the institution were in the kindergarten.
“Everyone has now been evacuated.”
Ambulance services, police and firefighters are working at the scene.
Mr Monastyrskyi, who was in charge of the Ukrainian police and other emergency services, is the most senior Ukrainian official to have died since the start of the war with Russia almost 11 months ago.
Anton Gerashchenko, advisor to the Minister of Internal Affairs of Ukraine, said: “Minister of Internal Affairs Denys Monastyrskyi, his 1st deputy Yevhen Yenin and Ministry’s state secretary Yurii Lubkovych died today in Kyiv region.
“My colleagues, my friends. What a tragic loss. Deepest condolences to their families.”
First lady Olena Zelenska was seen dabbing her eyes shortly before taking part in a World Economic Forum session in Davos, Switzerland.
She said: “Another very sad day today – new losses.”
UK foreign secretary James Cleverly tweeted: “Denys was a true friend of the UK. We are ready to support Ukraine in whatever way we can.”
The EU’s home affairs commissioner Ylva Johansson described Mr Monastyrsky as a “hero”.
“News of the death of Denys Monastyrsky, Yevhen Yenin and Yurii Lubkovich has shocked me deeply. My condolences to the families of all the victims of this tragedy. Denys is a true Ukrainian hero – over the last year leading with bravery and stoicism,” she said on Twitter.
“He was my friend. Working with him this past year was an honour. The EUHomeAffairs community and Interior Affairs Ministries in all 27 capitals, will feel this loss greatly. We will continue our work helping Ukrainians and helping Ukraine, in Denys’ memory. Slava Ukraini”