Ukraine says it will take time to determine the cause of a helicopter crash that killed 14 people.

Ukraine has established a commission to investigate the cause of a helicopter crash that killed 14 people including the country’s interior minister this week, an Air Force spokesman said on Thursday, but it will likely take weeks to reach a conclusion.

The helicopter came down on Wednesday near a kindergarten and a residential building in Brovary, a small town outside Kyiv, causing severe damage and panic among parents and children who were at the school. President Volodymyr Zelensky of Ukraine described it as a “terrible tragedy.”

The interior minister, Denys Monastryrsky, was one of Mr. Zelensky’s trusted advisers. The crash left a void at the top of the ministry just as Kyiv prepares for a possible Russian offensive in the spring and endures a barrage of missile and drone attacks on its energy infrastructure.

Ukraine will send six survivors of the crash abroad for treatment for burns, the deputy health minister, Iryna Mykychak, said. The six, who include children, are “the most difficult and complex cases” after the crash, she said, though she added in an appearance on Ukrainian television that “none of them is in a critical or life-threatening condition.”

They had already been transferred to a burn unit at a hospital in the capital, she said, giving no details about their onward destination. In all, 25 people were being treated in the hospital, including 11 children, Ukraine’s State Emergency Service said on Wednesday.

The officials aboard the helicopter had been traveling to a combat zone, according to Kyrylo Tymoshenko, the deputy head of the Ukrainian president’s office. Also killed, according to Ukraine’s Parliament, were Yevhen Yenin, the first deputy minister for internal affairs; and Yurii Lubkovich, the ministry’s state secretary.

The precise cause of the crash — whether mechanical failure, pilot error, environmental factors or sabotage — remains unknown. Yurii Ihnat, an Air Force spokesman, said on Ukrainian television on Thursday that an investigative commission would “take a lot of time” to reach its conclusion.

“Each part of the helicopter is collected, each detail can say something, give more information on what had happened,” he said. “It is not a matter of several days. It is necessary to fully establish, find out the details of what happened on that day.”

The crash came as Kyiv renews a diplomatic push for some of the most lethal armaments from allies, who worry that Ukraine’s military lacks time to break a deadlock with Russian forces before Moscow launches another ground assault.

Mr. Monastryrsky, the highest-ranking Ukrainian government official to die since Russia invaded in February, oversaw tens of thousands of Ukrainians fighting to defend their country as part of the police, national guard and border units.

He also directed the rescue and recovery efforts this week in Dnipro, where a Russian missile killed 45 people in one of the deadliest attacks on civilians in the nearly yearlong war.

In his nightly address on Wednesday, Mr. Zelensky said that Mr. Monastyrsky’s responsibilities had been reallocated and that the country’s head of national police, Ihor Klymenko, would lead the ministry until a replacement is chosen.