There was a risk to the entire region and all parties must pull back, the UN said at a meeting of its Human Rights Council in Geneva.

Instigated by the European Union, the session will decide whether to appoint an international team to investigate violations that rights groups say may amount to war crimes.

Ethiopia has dismissed the move as politically motivated. The meeting would embolden the Tigrayan rebels, its ambassador in Geneva said.

Mass arrests by the government continue, and 5-7,000 people are detained, including UN staff, the international body says.