Three people, including a NATO representative, were killed in Ukraine on Thursday when a missile accidentally exploded while being offloaded at a defense facility in the country’s northeast. Ammunition, including missiles, was being taken to a facility run by Ukroboronprom — a state-owned defense company — for disposal.

Ukraine was a part of the former Soviet Union and after it became an independent country, found itself with a large stockpile of obsolete ammunition and weapons which it has been slowly destroying. NATO, of which Ukraine is not a member, partly finances the disarmament of the Soviet-era weapons in Ukraine. The NATO representative who died in the accident was a Ukrainian who monitored the disarming process, according to local reports.

“There are three dead, including a representative of NATO, who oversaw the disposal of missile warheads,” Tetiana Myronenko, an employee of the Prosecutor's Office of Sumy — the region where the accident took place — wrote on Facebook, according to Interfax-Ukraine.

The other two killed in the explosion were test engineers, a TASS report said. A representative for the military prosecutor’s office for Ukraine’s central region said that two others had been injured in the explosion as well.

UkraineMissile A Ukrainian military vehicle damaged by an unexploded rocket shell is seen at the site of recent shelling near the village of Dmytrivka in eastern Ukraine, Sept. 19, 2014. Photo: REUTERS/David Mdzinarishvili