A helicopter crashed near a kindergarten outside Kyiv on Wednesday morning, killing least 18 people including Ukraine's interior minister and three children, authorities said. 
    The cause of the crash, which comes as the country's war with Russia approaches the 11-month mark, was not immediately clear. 
    At least 9 of those killed had been onboard the emergency services helicopter when it crashed in Brovary, a suburb about 15 miles northeast of the capital, national police head Ihor Klymenko said in a statement.
    The dead included Ukraine's interior minister, Denys Monastyrsky, his deputy, Yevhen Yenin, and state secretary, Yurii Lubkovych, Klymenko said.
    Ukrainian President Volodymyr Zelenskyy said in a statement that the number of dead was still being established, but of the death of three children he said: "The pain is unbearable."
    "May all those whose lives were taken this black morning rest in peace!” he said.
    At least 29 people, including 15 children, were being treated in hospitals, Oleksii Kuleba, the head of the Kyiv Regional Military Administration said. The extent of their injuries was not immediately clear.
    Kuleba said the helicopter fell near a kindergarten and a residential building. 
    "At the time of the tragedy, children and employees of the institution were in the kindergarten. At this point, everyone was evacuated," Kuleba said.
    Video and photos shared online by Ukrainian officials showed flames bursting from at least one building as smoke billowed up from the crash site.
    Ukrainian Prime Minister Denys Shmyhal said he had ordered a special commission to be created to lead an investigation into the circumstances of the incident.
    Yurii Ihnat, spokesperson for Ukraine’s Air Force Command, said the commission would include a number of aviation experts. "It is too early to talk about the causes of the crash," Ihnat said, speaking during a national telethon. 
    There has been no fighting reported around Kyiv for months, since Russian forces pulled back from the region after a failed assault on the capital.
    Officials in Ukraine and across Europe paid tribute to the dead. 
    “Tragedy far from the frontline, in Brovary,” foreign minister Dmytro Kuleba said on Twitter.
    “I wish a speedy recovery to those injured. Denys Monastyrskyi and Yevhenii Yenin were close colleagues & friends of mine, true Ukrainian patriots. Huge loss for all of us,” he said.
    Shmyhal, the prime minister, said it was “a great loss for the government team and the entire state." 
    "My sincere condolences to the families of all the victims," he said.
    “My colleagues, my friends. What a tragic loss,” interior ministry adviser Anton Gerashchenko wrote in a tweet.  “Deepest condolences to their families.”
    Olena Zelenska, Ukraine's first lady, could also be seen daubing away tears Wednesday morning before attending a World Economic Forum session in Davos, Switzerland, according to The Associated Press. 
    Forum President Borge Brende asked for 15 seconds of silence after opening the session to honor the Ukrainian officials killed in the crash.
    Tributes from officials from around the world also began to pour in on social media.
    The U.S. ambassador to Ukraine, Bridget A. Brink, said on Twitter that she was "shocked and saddened by the terrible news from Brovary."
    Charles Michel, president of the European Council, remembered Monastyrsky as a "great friend of the EU." 
    "We join #Ukraine in grief following the tragic helicopter accident in #Brovary," he wrote in a tweet offering his condolences to the families of the victims, as well as to Ukraine's leadership.