At least 11 illegal miners in northern Mozambique’s Montepuez ruby mine have died following a series of tunnel collapses over three days.

The mine is 75% owned by the UK-based natural resources firm Gemfields.

According to Gemfields, approximately 800 artisanal miners entered Montepuez Ruby Mining (MRM)’s Maninge Nice 3 mining pit.

Despite repeated warnings from MRM staff, these illegal miners were seeking ruby-bearing gems and began undercutting the outer edge of the mining pit. This led to several ground collapse incidents, killing 11 artisanal miners over three days.

MRM personnel provided humanitarian aid where required, stated Gemfields.

BBC cited Ministry of Mineral Resources and Energy general inspector Obete Matine as saying that the walls of one tunnel had first collapsed at the Montepuez site, killing one man.

The other miners continued digging despite the tunnel collapse, resulting in the death of two more miners following a second collapse.

There were eight additional deaths as illegal mining operations were not suspended.

Matine added that most of the victims were young people appointed by smugglers to extract precious stones from the mineral-rich region.

Gemfields’ involvement in the 2009-discovered Montepuez deposits started in June 2011, as part of a deal between Gemfields and original titleholder Mwiriti, under which Gemfields acquired 75% of the mine.

In June 2019, an accident at a copper and cobalt mine owned by British-Swiss mining firm Glencore in the Democratic Republic of the Congo (DRC) killed 43 illegal miners.

In March 2018, Mustang Resources secured a mining concession for the Montepuez ruby project.