Zeid Ra’ad Al Hussein highlighted "credible reports [of] widespread, systematic and shockingly brutal attacks"
The UN High Commissioner for Human Rights has warned that "elements of genocide may be present" in the treatment of Rohingya Muslims in Myanmar.
Myanmar's police and army launched a violent crackdown in the northern Rakhine state following attacks by Rohingya insurgents on police posts in August.
It is believed that thousands of people in the state have been killed or tortured by security forces, while human rights groups have documented partial or total destruction of Rohingya villages.
According to the United Nations, more than 620,000 Rohingya refugees are believed to have fled to Bangladesh since August 25th as a result of the violence.
UN High Commissioner for Human Rights Zeid Ra’ad Al Hussein addressed the organisation's Human Rights Council amid 'urgent concerns' over the situation facing the Rohingya people.
He highlighted the "staggering" number of people who have been forced to leave their homes, and "credible reports [of] widespread, systematic and shockingly brutal attacks".
He said authorities in Myanmar have refused to give his office access to Rakhine state, and called on officials to take action to "stop this madness now".
He argued: "Refusal by international as well as local actors to even name the Rohingyas as Rohingya – to recognise them as a community and respect their right to self-identification – is yet another humiliation, and it creates a shameful paradox: they are denied a name, while being targeted for being who they are.
"The Rohingya have been physically attacked, oppressed, deprived of nationality and rights. How much do people have to endure before their suffering is acknowledged and their identity and rights are recognised, by their government and by the world?"
Observing that Rohingya people have suffered "systematic and systemic discrimination" - as well as reports of widespread violence against them - Mr Zeid added: "Can anyone rule out that elements of genocide may be present?"
Last month, US Secretary of State Rex Tillerson said the situation in northern Myanmar constitutes an 'ethnic cleansing' against the Rohingya.