At least nine people died and four others were injured when a tantalite mine collapsed at Muiane, in the central Mozambican province of Zambezia.

The Zambezia provincial director of mineral resources and energy, Almeida Manhica, announced the disaster in the provincial capital, Quelimane, on Saturday and described the situation caused by illegal mining at Muiane as worrying.

Mozambique was once the world’s third largest producer of tantalite, thanks to Muiane and the nearby Morrua mine. But both were shut down in the 1980s, because of the war of destabilization waged against Mozambique by the South African apartheid regime.

Over the past decade attempts have been made to resume production at Muiane, but have run into resistance from illegal miners who vandalised equipment and occupied the mine. Thus in August 2014, about 800 people claiming to be former workers of the long defunct state company Minas Gerais de Mocambique (MAGMA), occupied the mine, which had been leased to the Canadian concern, Pacific Wildcat Resources.

Further disaster struck in November 2015, when illegal miners rioted at the mine, destroyed equipment and set fire to the site. Since then the area has essentially been in the hands of the illegal miners.

Illegal mining deprives the state of the resources which would flow from legal mining activities. It also damages the environment, and leads to tragedies, as artisanal miners are buried in landslides.