Eight people were killed during a protest against rising prices in Sudan's western Darfur region on Tuesday, the worst violence since tough austerity measures were imposed last month, police said.

Activists accused the police of using live ammunition to control the biggest anti-government protest since President Omar Hassan al-Bashir announced a cut in fuel subsidies and other austerity measures.

Buthina Mohamed Ahmed, a spokeswoman for the South Darfur state, which includes Nyala, declined to say whether live rounds had been fired, saying only an investigation had been launched.

Sudan has been mired in an economic crisis since South Sudan seceded a year ago, taking with it most of the crude oil production that is the lifeblood of both economies.

More than 1,000 people, mostly students, hurled rocks at police and blocked roads in the market area of Nyala, Darfur's biggest town, to protest against fuel price increases, witnesses said. Several buildings were damaged.

"Police were forced to act and exercised the minimum of force needed to control the situation, defend themselves and...protect properties which led to the death of eight citizens," police said in a statement on state news agency SUNA.

"A number of people were wounded, among them 24 officers, three of them seriously," the statement said, without saying whether police had used live ammunition. Several people had been detained, it added.

Protesters burned tyres in several streets and chanted "No to high prices" and "People want to change the regime", witnesses said.

Reuters