An illegal diesel refinery was discovered on Sunday near the town of Letnitsa in the region of Lovech, Northern Bulgaria, officials have announced.

Tanks full of diesel were found in and outside the facility which had a capacity of between 60 and 150 tons per month, Focus News Agency quotes Valentin Valkov, a Lovech district prosecutor, as saying.

Police is not providing more details for the moment as a probe is ongoing, but authorities suggested it was not immediately clear when the refinery had opened.