Ukrainian Defense Minister Stepan Poltorak has said that the probable cause of the fire at the defense ministry's arsenal in Svatove, Luhansk region, was the activity of pro-Russian militants.

"The causes and circumstances of the incident are now being determined. According to tentative information, the incident was a result of the actions taken by the enemy, who aim to destabilize the situation in the region," he said at a meeting of the Council of Reforms in Kyiv on Friday.

An ad hoc commission composed of the deputies of the defense minister, the deputy chief of the General Staff Armed Forces of Ukraine, and experts has been created to investigate the incident.

"They have already started to work. The results of the investigation will be made public," he added.

Poltorak also said that according to his information, four servicemen were injured in the fire, and one serviceman and one civilian, a local female resident, have died,

The fire had already been localized, he said. Twenty groups of 100 mine clearance specialists were created to clear the town of unexploded ordinance, he added.