An owner of a coal mine in the western U.S. state of Utah now says it will take at least a week to reach six miners trapped after a mine shaft collapsed early Monday.

Robert Murray, head of Murray Energy Corporation, which owns the Crandall Canyon coal mine, said late Tuesday that a new collapse inside the rescue area has driven rescuers back where they started more than 500 meters away from where the miners are believed to be.

He said while rescuers are working on the main tunnel to free them, they are also drilling two small holes to give the miners light and supplies. Those tunnels are expected to be ready in two to three days. Murray also said if the miners are still alive, they have enough access to water and oxygen to sustain themselves.

The Mexican consulate in Salt Lake City has confirmed that three of the trapped miners are Mexican citizens, although it has not released their names.

Some information for this report was provided by AFP, AP and Reuters.