Mutilated corpses washing up on the shores of a river in northern Burundi have raised fears of a return to violence in the central African nation, which is still recovering from a long civil war, according to dpa. Local officials said 14 bodies, many of them bound and slashed with machetes, have washed up on the River Rusizi since last week. Burundi's authorities blame bandits for the killings, dismissing fears that rebels may be returning to armed struggle. However, former rebel leader Agathon Rwasa disappeared before presidential elections earlier this year and is believed to be hiding in the bush in neighbouring Democratic Republic of Congo. President Pierre Nkurunziza stood unopposed in the election when opposition candidates boycotted the poll, accusing him of fraud. The disappearance of Rwasa, who was Nkurunziza's main rival, has raised fears he is reforming his rebel National Liberation Forces less than a year after they officially ended their rebellion. An estimated 300,000 people died in Burundi's conflict, which pitted mainly Hutu rebels against the Tutsi army.