Tunnel reinforcement specialists from a number of mining companies in Peru arrived at Cabeza de Negro Mine, 325 km (200 miles) south of Lima on April 9 to help with rescue efforts of nine trapped miners.
The crews will reinforce shafts at a copper mine in southern Peru where the nine workers have been trapped for four days, providing a boost for frantic relatives.
The addition of 20 specialists came after Oscar Valdes, cabinet chief to President Ollanta Humala, told reporters of new roof collapses inside the Cabeza de Negro Mine, Sky News reported.
The miners were trapped 250 m (820 ft) underground in a horizontal tunnel when a shaft collapsed on April 5.
The nine miners, aged 22 to 59 and including a father and son, were not injured and remain together. They were being supplied with oxygen, water and soup through a metal tube that they also use to communicate with rescue workers.
Some miners have been able to speak with relatives who are staying near the mine at an improvised camp of about 80 people that also includes police, firefighters and other miners.
While their health is generally considered sound, some of the miners are suffering from anxiety given the emergency situation.
Outside the mine on April 8, a group of rescuers cut wood beams to reinforce the tunnel walls.
Workers also used their hands and buckets to remove the debris obstructing the shaft. Before entering the mine, many chewed coca leaves in the belief that it would help them confront the difficult task.