CRYSTAL SPRINGS, Miss. (AP) — A spokeswoman for the Mine Safety and Health Administration says workers are searching for the bodies of two men who were buried in mud and slush at a gravel pit in southern Mississippi.

Amy Louviere said Sunday the effort has changed from a rescue to a recovery operation. 

Approximately 25 people are on site looking for the men.

The two men were operating heavy equipment for Green Brothers at a pit in Crystal Springs on Friday when they were completely buried in 10 to 12 feet of mud, slush and sluice.

The search continued Monday morning, NBC News reported.