GENEVA - The UN rights chief on Thursday urged the Sudanese government to avoid "heavy-handed suppression" as demonstrators gear up for mass protests on Friday.
"Tear gas, rubber bullets, live ammunition and other heavy-handed suppression will not resolve the frustrations and grievances of the people, Navi Pillay, High Commissioner for Human Rights, said in a statement.
Rights groups say scores of people have been arrested since the protests against inflation began on June 16 in the capital, Khartoum.
The protests spread after President Omar al-Bashir announced austerity measures including tax hikes and an end to cheap fuel.
Demonstrators in groups of 100 or 200 burned tyres, threw stones and blocked roads while calling for regime change.
In response, police officers fired tear gas at protesters in the eastern town of Kassala, witnesses said.
"After 23 years of endurance, the Sudanese people have decided to say enough is enough," said activist movement Sudan Change Now.
In her plea for calm, Pillay also called on Sudan "to immediately and unconditionally release those who have been detained for merely exercising their rights to freedom of assembly and expression.
"Reports of ill treatment in detention are very worrying and must be investigated promptly."
She also urged protestors to ensure, on their part, that no violence or damage to property takes place during the demonstrations.
Sudan has lost billions of dollars in oil receipts since South Sudan gained independence last July, taking with it about 75 percent of Sudanese crude production.
Pillay's statement comes after Sudan rounded on the United States for criticising its handling of the protest movement.
"The USA is not qualified to advise on such an issue because it continues bombing civilians in different parts of the world and it cracked down on demonstrators on Wall Street," foreign ministry spokesman Al-Obeid Meruh said on Wednesday.
He was responding to comments by US State Department spokeswoman Victoria Nuland who said that "arresting and mistreating protesters" will not solve Sudan's political and economic crises.
"There have been reports of protesters being beaten, imprisoned and severely mistreated while in government custody. We call for the immediate release of those detained for peaceful protest," she said.