A search was under way after an accident at an underground gold mine in northern Nevada left two miners missing and feared dead.
Barrick Gold Corp. has not confirmed any deaths following Thursday's accident at the Meikle mine, which has seen three fatalities in the past 11 years.
But a company official referred to the search as a "recovery effort" directed by the U.S. Mine Safety and Health Administration.
"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.
Lang said the initial investigation was focused on a hoist in the ventilation shaft of the mine, which is about 55 miles northwest of Elko and 275 miles northeast of Reno.
An official for MSHA in Washington, D.C., told The Associated Press that two workers were being lowered into the shaft when the hoist operator noticed a "large surge of pressure on the hoist drum" and the mine was evacuated.
The two workers "have not been located," said the official, who was not authorized to disclose the information publicly and spoke on the condition of anonymity.
The state has seen a surge in gold mining in recent years as prices skyrocketed and miners stepped up exploration, especially along the Carlin Trend — one of the largest known ore deposits, stretching about 40 miles long and 5 miles wide in northeast Nevada.
The accident occurred at about 1:15 a.m. at the mine with about 300 workers. Toronto-based Barrick notified the missing miners' families and shut down the mine's underground operations, Lang said.
Elko police Lt. Richard Genseal said the Elko Bomb Squad was assisting in the search with a robot fitted with a camera.
The mine, which is operated by its subsidiary Barrick Goldstrike Mines, has had three deaths in three separate accidents since 1999, according to MSHA records. The most recent was in August 2004 when a truck driver was pinned between his truck and a cement pillar. Another truck driver was killed in February 2000 when he backed his water truck into an open slope, was ejected and fell 75 feet below.
In April 1999, a miner was cleaning debris from a rock blasting area, lost his footing and fell into an opening about 150 feet to his death, the MSHA records show.
Barrick, the largest gold company in the world, owns several mines in Nevada — the fourth largest producer of gold in the world behind South Africa, Australia and China.