Tanzania has invited companies to bid for a large-scale logging project in one of Africa's most precious game reserves.

It intends to sell millions of trees in the Selous game park, which is a Unesco world heritage centre.

Selous in southern Tanzania is home to black rhinos, elephants, lions, rare birds and other species. It has an exceptionally high variety of habitats, ranging from swamps to rain forests.

Conservationists have already expressed concern about plans to build a vast hydroelectric plant on a river in the game reserve.