Officials at the Kranj police administration have told the STA that crime investigators are working with forensic experts to establish the cause of the explosion in the oven that caused the fire.
The investigation would also show whether the man servicing the oven was authorised for the job, being specialised in plumbing maintenance.
Apart from the serviceman, six employees and two firefighters were injured in the explosion and the ensuing fire at the Excenter metal fittings plant in Hrastje near Kranj.
The blast and the fire completely destroyed the roof and the first floor of the building. Initial estimates put the damage at EUR 300,000.
Another fire broke out early on Friday at a barn on a farm near Grosuplje, southeast of Ljubljana. Dozens of pigs were killed, while the owners managed to rescue the horse and farm machinery.
The initial damage estimate is EUR 10,000.