Ukrainian Interior Minister Denys Monastyrskyi, other Ukrainian officials, and three children are among the 18 people killed when an emergency services helicopter crashed Wednesday in the eastern Kyiv suburb of Brovary, Ukrainian authorities said. Monastyrskyi, his deputy Yevhen Yenin, and state secretary of the ministry Yurii Lubkovych were among the nine people killed aboard the helicopter, while nine others were killed and 29 injured on the ground, including 15 children. 

The helicopter crashed near a kindergarten, Kyiv Regional Governor Oleksii Kuleba said. 

Monastyrskyi, the minister in charge of Ukrainian police and other emergency services, is the most senior Ukrainian official killed during the 11 months of Russia’s invasion, though there is no evidence yet that the crash was related to the war. “It was dark and foggy at the time of the crash and initial reports suggest the helicopter hit the nursery before crashing close to a residential building,” BBC News reports.

“For now, we are considering all possible versions of the helicopter crash accident,” Ukraine’s prosecutor general, Andriy Kostin, said on Telegram. 

Monastyrskyi, 42, “was a prominent member of President Volodymyr Zelensky’s cabinet and played a key role in updating the public on casualties caused by Russian missile strikes,” BBC News reports. One such Russian strike in Dnipro over the weekend killed at least 45 Ukrainian civliains in an apartment building.

“Zelensky and other senior leaders have remained in Kyiv in a show of resistance, even when Russian forces fought their way to the edge of the capital in the early days of the war,” The Wall Street Journal notes. There hasn’t been any fighting reported near Kyiv for months.

Monastyrskyi’s death prompted 15 seconds of silence at the World Economic Forum in Davos, Switzerland, where first lady Olena Zelenska was seen visibly upset.