The top U.N. human rights assembly has approved by consensus a resolution calling for the quick deployment of experts to Burundi to look into abuses amid spiraling violence in the east African country.

After a U.S.-led diplomatic push, the 47-member Human Rights Council — which counts Burundi among members — approved the text that calls for the U.N. human rights chief to send in a mission of experts who are to report regularly on the rights situation there.

The day-long debate Thursday among diplomats and advocacy groups was marked by a defense of Burundi's security forces by a government representative, and teary testimony by Pierre Claver Mbonimpa, a rights advocate who was tortured.

The U.N. human rights chief, Zeid Raad al-Hussein, told the council that at least 400 people have been killed since April 26, and nearly 3,500 arrested in the political crisis. He said at least 220,000 people have fled the country.

Earlier this month, Thomas Perriello, the U.S. Special Envoy for Africa's Great Lakes region, said that Burundi is on the brink of civil war. Many fear clashes there could lead to violence like the 1994 massacres in nearby Rwanda.

The violence is linked to President Pierre Nkurunziza's third term in office, which many Burundians and foreign observers had opposed as unconstitutional and in violation of a peace accord.

The treaty ended a civil war in which 300,000 people were killed between 1993 and 2006.

Wire services