The UN has appointed a Senegalese diplomat to facilitate talks between rival factions in Burundi's political crisis after the opposition accused the previous mediator of bias.
The UN said in a statement that Abdoulaye Bathily, who is already the UN's Special Representative for Central Africa, would arrive in Bujumbura on Sunday to help mediate talks.
"The secretary-general has requested ... Abdoulaye Bathily, to offer good offices in Burundi in support of regional efforts to reduce tensions and help Burundians peacefully settle their differences," the UN said in a statement, referring to Ban Ki-moon, the UN chief.
The East African country descended into turmoil in late April after President Pierre Nkurunziza said he would seek a third term.
Opposition protesters took to the streets for weeks, saying the move violated the constitution and a peace deal that ended an ethnically charged civil war in 2005.
The previous UN mediator, Said Djinnit, left the role after only a few weeks having faced criticism from the opposition that he was biased towards the government, a charge he dismissed.
Djinnit remains the UN special envoy to the Great Lakes region.
A series of elections have been delayed by weeks of unrest and violent clashes between police and protesters, alarming a region which has a history of ethnic killing.
Philippe Nzobonariba, Burundi government spokesperson, welcomed Bathily's appointment but said the country would not budge on the timings of forthcoming parliamentary and presidential elections, due to take place on June 29 and July 15.
Earlier, on Saturday, 11 policemen were wounded in the capital Bujumbura when unknown assailants hurled grenades and attacked a police station, according to police officials.
"Yesterday police posts were attacked, and the police registered 11 policemen who were wounded in the attack," Pierre Nkurikiye, a police spokesperson, told Reuters news agency.