Chilean Health Minister Jaime Manalich said Wednesday that they are trying to keep the 33 trapped miners mentally and physically healthy to facilitate their rescue, which could take three to four months.

The miners were plunged into darkness by the Aug. 5 collapse of a copper mine under a barren mountain in northern Chile's Atacama desert.

They lived on what was supposed to be a two-day emergency food supply under the mine when rescuers finally reached them 17 days later.

The rescuers had drilled a narrow bore-hole down to their living-room-sized shelter, but it might take three to four months to dig a hole wide enough to get them out.

The miners have already begun receiving high-protein foods and vitamins, which were sent to them through a plastic tube.

Authorities also sent video and sound equipment into the mine to keep in touch with the miners and provide them with psychological assistance.

Manalich said that authorities will send them articles like thermometers to determine each miner's state of health and which medicines to send to them.

He said that authorities are also installing equipment to improve the air quality inside the mine.

The miners will also receive psychological assistance and a daily exercise routine to avoid muscular atrophy or immobility in their joints. As the environment inside the mine is very humid, they also have to protect their skin from infections.

On Wednesday morning, an earthquake measuring 4.5 degrees on the Richter scale hit near the mine where the miners are trapped, however, there were no reports of victims or damages.