Four workers suffered critical burns over 50 percent or more of their bodies while melting iron at a steel mill Friday morning in central Bangladesh, local media report.

At about 4 a.m., five workers were hit with hammerscale, a flaky byproduct of iron forging, while laboring at an SS Steel Mills Limited factory in Gazipur. Two suffered 90 percent burn injures while two were burned over half their bodies.

The fifth worker was treated and released.

Coworkers took the five to a hospital in Gazipur for treatment. A spokesperson for the local fire department reports that they were not notified of the accident.

Production continues at the steel mill.