LUSAKA, Zambia, (AFP) — More than 30 people were feared trapped underground after a pit collapsed in a Zambian copper mining region, a minister said.

“May I just inform the nation that we have a tragedy brewing in Chingola,” Home Affairs Minister Jack Mwiimbu told parliament.

“We have more than 30 people under the rubble” in a makeshift mine, he added, without giving further details.

Zambia is one of the world’s largest copper producers and Chingola is in the country’s Copperbelt Province, a region that is a hotbed of illegal open-pit mining for the red metal.

Mines minister Paul Kabuswe told journalists on Friday night that “nobody has been found or rescued”.

As a result, “we cannot say exactly how many people are trapped under this rubble”, he said at the Chingola site, about 400 kilometres (250 miles) north of the capital Lusaka.

Copperbelt Province has one of the world’s largest open-cast copper mines and some of the waste piles reach up to 100 metres (300 feet) in height.