A view shows one of the galleries during a rescue operation inside Perkoa mine where water is still being pumped out, four weeks after a flood trapped eight miners inside the galleries, in Perkoa, Burkina Faso, May 13, 2022.
A view shows one of the galleries during a rescue operation inside Perkoa mine where water is still being pumped out, four weeks after a flood trapped eight miners inside the galleries, in Perkoa, Burkina Faso, May 13, 2022. Reuters / ANNE MIMAULT

Rescue workers have found no survivors in a rescue chamber deep inside a flooded zinc mine in Burkina Faso, the government said on Tuesday, all but extinguishing hope that eight missing miners could still be alive after a month.

The Perkoa mine, owned by Canadian firm Trevali Mining Corp and located about 120 km west of the capital Ouagadougou, was abruptly submerged on April 16 after torrential rain fell unexpectedly during the country's dry season.

There had been some hope during a month-long search and rescue operation that the missing men might have reached the rescue chamber, which is stocked with food and water and located around 570 metres below ground.

"The rescue teams have opened the refuge chamber, unfortunately it is empty," the government's information service said in a statement posted on social media.

"Everything suggests that the miners were unable to reach the refuge chamber at the moment when the flood happened and searches are ongoing," the statement said.

Trevali said in its own statement, released shortly after the government's one, that the refuge chamber had been found intact with no one inside.

Distraught relatives of the missing men have been gathering every day at the site in the Sanguie province, seeking solace from each other as they faced the agonising wait for news.

Both the company and the government have launched investigations into the causes of the incident.

The Perkoa mine consists of an open pit with underground shafts and galleries below. Most of the workers who were there at the time of the flash flood were able to escape, but the missing eight were more than 520 metres (1,706 feet) beneath the surface.

Six of the missing men are Burkina Faso nationals, one is from Tanzania and one from Zambia.

(Writing and additional reporting by Sofia Christensen and Estelle ShirbonEditing by James Macharia Chege)