IRKUTSK, Russia -- An underground oil tank caught fire early Tuesday in the Siberian city of Angarsk, leaving two people missing and one injured, local media reported.

The fire occurred when workers were inspecting the pressure in the oil tank, said the Ministry of Emergency Situations.

The oil tank on fire is located at Angarsk city's industrial site, having a capacity of 500 cubic meters.

The fire has been put under control, yet the cause of the accident remains unknown.