The cause of the accident, which comes as the country’s war with Russia approaches the 11-month mark, was not immediately clear.
At least nine of those killed were on board the emergency services helicopter when it crashed in Brovary, a suburb about 24 km northeast of the capital, said Ihor Klymenko, the national police chief, in a press release.
He said the dead included Ukrainian Interior Minister Denys Monastyrsky, his deputy, Yevhen Yenin, and Yurii Lubkovych, the state secretary. A child was also among the dead, officials said.
Authorities had previously put the death toll at 18, including four children, but it was later revised down as authorities stressed the final figure was uncertain.
“The pain is unbearable,” President Volodymyr Zelenskyy said.
“May all whose lives were taken this dark morning rest in peace!” he said in a statement.
At least 25 people, including 11 children, were being treated in hospitals, officials said. The extent of their injuries was not immediately clear.
The helicopter fell near a kindergarten and a residential building, according to Oleksii Kuleba, the head of the Kyiv regional military administration.
“At the time of the tragedy, the children and the employees of the establishment were in the kindergarten. At that time, everyone was evacuated,” he said.
Videos and photos shared online by Ukrainian officials showed flames shooting from at least one building as smoke billowed from the crash site.
Ukraine’s security service said on its Telegram channel that it was considering at least three possible causes, including a malfunction, violation of flight rules or “deliberate actions aimed at destroying the vehicle”.