“On approach to the Luhansk airport a Ukrainian armed forces military transport Il-76 airplane was shot down with an antiaircraft rocket system,” the prosecutor general’s office said in a statement. “In addition to the nine crew members, 40 military personnel were on board. All of them died.”

The statement said the office had opened an investigation into what it called a terrorist act.

Video of the incident showed an explosion near the surface of the landing strip where the plane was said to be making its final approach into Luhansk. It was carrying troops being rotated into eastern Ukraine, military equipment and food, the ministry of defense said in a statement. The defense ministry gave no details of the casualties, but offered “sincere condolences to the parents, the relatives and loved ones of the soldiers in connection with this tragic and irreparable loss.”