An explosion at the Arsenal military plant in Kazanlak, Bulgaria, has killed one worker, regional authorities reported Thursday.

The incident, which occurred during working hours, has prompted an urgent investigation into its cause.

According to preliminary reports, a fierce fire broke out in one of the plant’s workshops, triggering a powerful explosion and shock wave that caused significant damage to the facility’s interior. Emergency services rushed to the scene, but one employee was confirmed dead, as reported by Bulgarian broadcasters BNT and Nova TV.

Details about the ignition and the events leading to the detonation remain unclear. Authorities are working to determine the exact circumstances of the accident.

This marks the second incident at the Arsenal plant in recent months. On 19 May, a worker at Plant 3’s workshop 120 suffered burns to the hands and face in a fire involving nitroglycerin. The worker was treated in Plovdiv and survived.

Officials have yet to release further details, but updates are expected as the investigation continues. (ILKHA)