Mashood Adebayo Baderin, an independent expert advising the United Nations on the human rights situation in Sudan, said he was concerned by the state of affairs in the country.
His office said Thursday as many as 50 people were reportedly killed in a government crackdown on demonstrators protesting against a cut in fuel subsidies. He said at least 800 people, ranging from opposition leaders to journalists, were held incommunicado by state authorities.
"I strongly condemn the use of violence against peaceful demonstrators and the destruction of public property during demonstrations," he said in a statement. "I urge both the government and the demonstrators to completely refrain from resorting to violence."
The Sudan Tribune, an independent newspaper, said there was a growing chorus of voices calling on Sudanese President Omar Bashir to step down. He blamed outside elements for the deaths reported during last week's demonstrations.
Baderin said he's heard reports from "various sources" that said Sudanese forces fired lived rounds at protesters last week.
He said he was calling on Sudanese officials to "conduct prompt, thorough and impartial investigations into these incidents, and to hold those responsible to account."