The Burundian authorities say that between one- and two-hundred people have been killed in fighting between Rwandan and Burundian rebel groups.

The clashes reportedly broke out last week, in western Burundi not far from the capital, Bujumbura.

An army spokesman said many of the fighters, including ten Rwandans, had surrendered and the army was tracking down others who had fled.

There has been no independent confirmation of the clashes and the BBC East Africa correspondent says repeated efforts by western diplomats have failed to elicit evidence from the Burundian authorities of a large Rwandan rebel presence. Our correspondent says the two rebel groups have been helping each other against their respective governments.

But the army spokesman said it was believed the Rwandans -- many of whom belong to the extremist Interahamwe militia -- feared the resumption of the Burundian peace process later this month would mean an end to the alliance.

From the newsroom of the BBC World Service