Rescuers were preparing to lower sound-detection equipment into a northern Chilean gold and copper mine in an effort to locate 33 workers trapped there.
The listening devices would be lowered through holes drilled down into the mine in hopes of making contact with the workers, who were trapped on Thursday when a tunnel collapsed, said Rodrigo Jofre, who represents families of the 33 trapped miners.
The equipment should reach the bottom of the San Jose mine by Monday, rescue worker Luis Salazar said.
Three teams of rescuers entered the mine on Saturday through a ventilation shaft, but had to withdraw when rock collapsed in the duct.
The fate of the missing workers was not known. There had been no contact with the miners since the collapse.
Officials still held out hope some of the miners survived by reaching an underground shelter containing oxygen, food and other supplies.
In 2007, an explosion at the San Jose mine killed three workers.
It is owned by private mining company San Esteban.