Police say four workers have been injured in an explosion at a Middle Tennessee plant where a January accident killed a worker.

Gallatin Police Lt. Kate Novitsky said the accident at the Hoeganaes Corp. plant was reported at 6:37 a.m. Friday.

Novitsky said two injured workers were taken to Vanderbilt University Medical Center in Nashville. The extent of injuries to the other two employees wasn't immediately clear. The names of the victims weren't immediately released.

The plant makes metal powders for automotive and industrial uses.

A Hoeganaes official said the company didn't immediately have a comment.

This is the third accident at the plant this year. A Jan. 31 flash fired killed one worker and seriously burned another. A similar fire occurred on March 29 caused one injury.