A Ukrainian representative of NATO was among the three people who died in an explosion during the offloading of munitions at a trial station belonging to the state-run concern Ukroboronprom on Thursday, an employee of the Prosecutor's Office of Sumy, Tetiana Myronenko, has said.

"There are three dead, including a representative of NATO, who oversaw the disposal of missile warheads," Myronenko wrote on her page on Facebook.

According to her, the NATO representative was a citizen of Ukraine. He helped in the implementation of a joint program with NATO aimed at assisting Ukraine in ammunition disposal.

As reported, three people were killed and another two injured in an explosion on the grounds of a trial station No. 2 of the state corporation Ukroboronprom's State Scientific Research Institute of Chemical Products in Krolevets district, Sumy region, Ukraine.

The explosion occurred at around 4:30 p.m. on Thursday, reportedly during offloading of the ammunition intended for disposal, a spokesperson for the military prosecutor's office in Ukraine's central region said.

"It has been tentatively established that the ammunition brought in for disposal exploded during the offloading. As a result, three people have been killed and another two sustained injuries," the spokesperson said.