An ammonia leak at a poultry processing plant in North Carolina has killed one person and injured three others, authorities said.

The leak occurred Saturday at the Mountaire Farms plant in Robeson County in southern-central North Carolina, about 16 miles south of Fayetteville.

County Emergency Management Director Charles Britt told The Fayetteville Observer that the leak has been contained. The three injured have been taken to the hospital.

It was not immediately clear how the person died or what caused the leak.

A call to Mountaire Farms was not immediately returned Saturday. However, the company issued a statement expressing condolences for the victims and promising to cooperate with authorities.