The United Nations refugee agency says more than 5,800 Burundians have crossed into Rwanda since the end of last month amid fears of violence ahead of elections later this year.

UNHCR said in a statement Wednesday that hundreds are crossing the border daily, most of them children. About 800 of the refugees arrived in Rwanda on Tuesday alone.

That statement said the refugees cite disappearances of relatives and pressure to pledge allegiance to the ruling party among reasons for fleeing their country.

Human Rights Watch has been warning of growing tension in Burundi, where peace activists and the opposition want President Pierre Nkurunziza to step down when his current term expires.

Nkurunziza has not publicly said if he will seek a third term.