GENEVA, Sep 10 (AFP) - Faced with allegations of grave violations in China and Russia, the UN body created to address rights abuses seems paralysed by uncertainty on how to respond.

The UN Human Rights Council, which will host a month-long session in Geneva from Monday (Sep 12), frequently acts to investigate and rein in abuses inside countries.

But that task is trickier and more fraught when the countries involved are among the world's most powerful, and permanent members of the UN Security Council.

Human rights council members have long shied away from taking on the two heavyweights directly, but a damning United Nations report on violations in China's Xinjiang region and concerns over an intensifying crackdown inside Russia have spurred calls for action.

Yet fears abound that a failed attempt to hold either country accountable would signal a shifting power balance and weaken the council.

"The way the council builds its response will influence its capacity to address the most serious situations in the years to come," a European diplomat told AFP.

"What is at stake is the vision of the universality of human rights, the vision of the role of the human rights council."