Volkswacht Bodensee - Search intensifies for five trapped in giant Chile copper mine

At least 100 people were involved in the perilous search effort nearly 12 hours after the event was registered, said Andres Music, general manager of El Teniente mine in Rancagua, some 100 kilometers (62 miles) south of Santiago.

"So far, we have not been able to communicate with them. The tunnels are closed, they are collapsed," he told reporters on Friday.

The miners had been working at a depth of more than 900 meters when the collapse happened. Their exact location has been pinpointed with specialized equipment.

Michael Miranda, brother of missing miner Jean Miranda, 31, told AFP the men's families were desperate for news.

"They haven't explained anything to us. No one has approached us to talk to us, to tell us if my brother is okay or not," he said outside the offices of state mining giant Codelco in Rancagua.

Jean's wife was pregnant, he added, "and no one from the company has approached her to talk. No psychological support, nothing."

Mining minister Aurora Williams earlier announced the temporary cessation of activity at the mine, which began operating in the early 1900s and boasts more than 4,500 kilometers (some 2,800 miles) of underground tunnels.

Last year, El Teniente produced 356,000 metric tonnes (over 392,000 tons) of copper -- nearly seven percent of the total for Chile.

- 'Many irregularities' -

The cave-in happened after a "seismic event" Thursday afternoon of which the origin -- natural or caused by drilling -- is not yet known, according to authorities.

The tremor registered a magnitude of 4.2.

"It is one of the biggest events, if not the biggest, that the El Teniente deposit has experienced in decades," said Music.

Jose Maldonado, a union leader at El Teniente, said workers were demanding a "thorough investigation" and told AFP they had reported "many irregularities."

The search team included several of the rescuers who participated in successfully surfacing 33 miners trapped in a mine for more than two months in the Atacama Desert in 2010, attracting a whirlwind of global media attention.

Chile is the world's largest copper producer, responsible for nearly a quarter of global supply with about 5.3 million metric tonnes (5.8 million tons) in 2024.

Its mining industry is one of the safest on the planet, with a fatality rate of 0.02 percent last year, according to the National Geology and Mining Service of Chile.

The metal is critical for wiring, motors and renewable energy generation.

D.Schlegel--VB