A cassiterite mine has collapsed in Burundi leaving at least six miners dead and three others injured.

The authorities in Kayanza province said the miners were digging illegally for cassiterite, which is the main ingredient for tin, reports BBC.

Mining companies in Burundi reportedly use crude methods of extraction and safety is poor.

The mine fields in the northern province of Kayanza are also rich in colombo-tantalite ore, used to make mobile phones.