The United Nations refugee agency says as many as five-hundred people a day are now arriving in western Tanzania after fleeing increased fighting in Burundi.

The UN said refugee numbers were significantly higher than for last month.

Many arrived wearing several layers of clothing because Burundian soldiers near the border were reportedly preventing them from taking baggage with them.

Some refugees told UN officials that Hutu youths of military age had disappeared in northern Burundi.

The human rights group, Amnesty International, has warned of an escalation of cases of torture, disappearance and summary executions. It said the country was on the verge of a humanitarian and human rights crisis.

The minority Tutsi forces in Burundi are engaged in a long-running civil war with their Hutu rivals.