(CNN) -- Rescue crews Thursday were searching for two miners after an incident at a mine in Elko County, Nevada, a U.S. Mine Safety and Health Administration official told CNN.
The incident occurred at about 1:15 a.m. Pacific Time (4:15 a.m. Eastern), according to operator Barrick Gold Corp. All underground operations at the Meikle mine were suspended.
Two workers were being lowered into a ventilation shaft when the person operating the hoist noticed a large surge of pressure on the hoist drum, said the federal official familiar with the case. The mine was evacuated, and three mine rescue team members were sent in to investigate.
The mine safety agency, which has officials on site, is leading the "recovery operation," the company said in a statement.
"While we don't have all of the facts at this point, what we do know about the incident is not encouraging," said Greg Lang, president of Barrick's North America Region. "We are working with MSHA as the recovery operation continues."