JOHANNESBURG (REUTERS) - South African gold producer Harmony Gold launched a rescue operation on Wednesday to free 17 miners trapped a mile underground after a fire at its Doornkop mine near Johannesburg.

The company said it had made contact with eight miners, who had managed to flee to a refuge bay at a depth 1,700m. The whereabouts of the remaining nine miners was unknown, a company spokesman said.

Rescue teams had been sent underground but access to the affected area has being hampered by smoke and a subsequent rock-fall, the spokesman added.

South Africa's gold mines are among the deepest in the world.