Iran announced on Saturday that it had shut down its Shazand refinery in Arak province due to technical failures, reported Press TV.

A fatal incident had occurred on September 16, raising the number of deaths at the refinery to six over the past year. At least 19 others have also been wounded.

More incidents had occurred in recent months. A gas leak injured five people in May.

This is not the first time the refinery has been shut down, according to Cihan News Agency.

The refinery’s RFCC unit had gone offline several times due to such technical problems last year, reducing the refinery’s Euro 4 gasoline production – originally 8-9 million liters per day – by nearly half.

Shazand is Iran’s largest gasoline production unit and also produces half of the country’s total gas oil production at 12 million liters per day.