OTTUMWA, Iowa – An ammonia leak forced Cargill to stop production at one of its pork processing plants, according to the company.

The leak was detected at 2 a.m. Jan. 10, and the plant was evacuated. Two workers were hospitalized, but their injuries were not life-threatening. Mike Martin, a spokesman for Cargill, said a leak in a valve was the problem.

Company officials had planned to resume operations by the afternoon for the second shift, but later decided to cancel the second shift. The plant will run two full shifts on Jan. 11, Martin said. The Ottumwa plant employs 2,400 workers and processes 18,000 to 19,000 hogs per day.