PARSONS, Kan. (AP) _ An explosion ripped through the Kansas Army Ammunition Plant on Wednesday, killing two people and injuring four others.

The cause of the 4:20 p.m. explosion was not immediately known, said a spokeswoman for Day and Zimmermann Inc., the private contractor in charge of manufacturing. The plant, which is owned by the U.S. Army, makes several types of munitions.

Employees who refused to be identified said the explosion occurred on a production line where components for cluster bombs are made. The company would not confirm that the line was the site of the blast.

The names of the dead were not immediately released.

Jerry Lilley, administrator at Labette County Medical Center, said three people were treated for abrasions and discharged. One worker was listed in good condition, being treated for abrasions and shrapnel wounds in his arms, trunk and face.

Manager Carl Wilson said the 1,400-employee plant stopped operation Wednesday evening. Most of the plant would resume operating Thursday morning, the company said.