The violence broke out in the southern forest region early Monday when petrol station guards from the Guerze tribe in the town of Koule beat to death an ethnic Konianke youth they had accused of stealing.
Fighting quickly spread to the nearby provincial capital N'Zerekore, 570 kilometres (350 miles) southeast of Conakry, leaving homes destroyed and at least 80 people wounded.
The doctor, from a N'Zerekore hospital, said the death toll would continue to rise as bodies in the mortuary had not been identified because several "have no head, while others have no identity papers".