Burundi's ruling party, the CNDD-FDD, picked its secretary general, Evariste Ndayishimiye, as its candidate in a presidential election scheduled for May, it said on Sunday.

Ndayishimiye, 52, also heads the department of military affairs in the president's office and has served as minister of the interior and security.

Current President Pierre Nkurunziza will not seek re-election.

Nkurunziza's decision to run for a third, five-year term in 2015 sparked widespread protests and violence. His party has welcomed his decision to stand down, conferring on him the title of "Supreme Guide of Patriotism" and lavish send-off perks including a villa worth $530 000.

Burundi is one of the world's poorest countries and lost donor funding after the political violence following the 2015 election. Its GDP per capita was $270 per person in 2018, World Bank statistics show.

In September, the United Nations warned that police, security forces and the ruling party's youth league, the Imbonerakure, were committing serious human rights violations.

Those included killings, disappearances, torture and gang rape of alleged political opponents, and that violence was likely to spike as polls approached. Burundi condemned these accusations.