Opposition MPs in Burundi, who say they have been receiving death threats, have asked the UN chief for protection.
President Pierre Nkurunziza came to power after a peace process
The 46 politicians have written an open letter to UN Secretary General Ban Ki-moon outlining their concerns.
They allege a death-list has been drawn up of 350 opposition members. The government has not responded.
Two local opposition politicians have been killed in recent weeks in the country which is emerging from a 12-year civil war.
The BBC's Prime Ndikumagenge in the capital, Bujumbura, says the MPs want the international community to intervene before it is too late - not only for the sake of their protection but also to save the democracy which it helped to foster.
President Pierre Nkurunziza came to power in 2005 after elections - the final step in a peace process intended to end years of fighting between Hutu rebels and the Tutsi-dominated army.
But in the last year the country has been awash with divisive political disputes.
Parliament is currently deadlocked over the appointment of a speaker, and has not passed any legislation for a month.
Earlier in February, the leader of Burundi's main opposition party, the Front for Democracy in Burundi, was severely wounded in a grenade attack which killed his wife and baby.
One rebel group still remains active, although under South African mediation it is hoped the Forces for National Liberation (FNL) will soon return to the negotiating table.