The United Nations (UN) human rights chief said on Friday that he was deeply disturbed by the escalating crisis in eastern Congo, urging all those with influence to help halt the violence and warning of a risk that it spreads beyond the country's borders.

"If nothing is done, the worst may be yet to come, for the people of the eastern DRC (Democratic Republic of Congo), but also beyond the country’s borders," Turk told an emergency meeting of the Geneva-based Human Rights Council.

"All those with influence must act urgently to put an end to this tragic situation."

Congo called the meeting and is asking for it to urgently investigate massive human rights violations it says have been committed by Rwandan-backed M23 rebels in eastern Congo who have taken the city of Goma and are seizing more territory.

"It is urgent to exert international pressure so that Rwanda ceases its support of the armed groups and withdraws from the Congolese territory as soon as possible," Congo's Minister of Communication Patrick Muyaya told the packed meeting room.

Rwanda rejected responsibility and warned that it was itself at risk of attack from its neighbour. "We categorically oppose the DRC's attempts to portray Rwanda as being responsible for its instability in the eastern DRC," said James Ngango, ambassador of Rwanda to the United Nations in Geneva.

"What is clear, however, is the imminent threat the current situation poses to Rwanda. Following the fall of Goma, new evidence has come to light regarding an imminent, large-scale attack against Rwanda," he alleged, adding that there was a stockpile of weapons around the airport.