AN investigation has been launched to determine the cause of the underground explosion that killed seven miners at the Beatrix gold mine near Welkom on Monday. Part of the mine was shut down on Monday evening pending the outcome of a meeting with Mineral and Energy Affairs Minister Phumzile Mlambo-Ngcuka, National Union of Mineworkers representatives and mine management. Gold Fields spokeswoman Sandra Mackintosh said five of the victims were from Lesotho, one was a Mozambican and the other was a a South African. The bodies of the seven miners were recovered at 2pm on Monday from the level 16 shaft.