Rescue teams digging to free 65 miners in Mexico suffered a setback Tuesday when part of their rescue tunnel caved in.
Mine officials say the collapse forced them to retreat and try to start over. The miners have been trapped in a northern Mexico coal mine since Sunday.
A rescue team from the United States was expected to arrive at the Pasta de Conchos mine in Coahuila state. The search has gone slowly because rescue crews are using only hand tools, fearing power machinery could trigger another blast.
Officials say the miners were carrying only a few hours' worth of oxygen with them, but they believe the mine's ventilation system is still working.
The miners are believed to be about three kilometers from the mine's entrance.
Family members have set up camp outside the entrance, braving bitterly cold temperatures with blankets, bonfires, and hot drinks.
Some information for this report was provided by AFP.