File picture: AP Photo/Bram Janssen.

Khartoum - A student demonstrator was killed Thursday in eastern Sudan, a local official and relatives told AFP, amid mounting protests over the rising price of bread.

"The situation in Al-Qadarif is out of control and the student Moayed Ahmad Mahmoud was killed," said Mubarak al-Nur, a lawmaker in the city 550 kilometres (340 miles) from the capital Khartoum.

Mahmoud was a university student, he said.

Nur called on authorities "not to use force against demonstrators, who are asked to peacefully exercise their right" to protest.

A government decision to raise the price of bread this week from one Sudanese pound to three (from about two to six US cents) sparked protests across the country on Wednesday.

Angry protesters on Thursday set fire to the headquarters of President Omar al-Bashir's National Congress Party (NCP) in two locations, witnesses said.

Demonstrators in Al-Qadarif "threw stones at banks (in the city centre) and smashed cars," resident Tayeb Omar Bashir told AFP by phone.

They then "moved to the ruling party headquarters near the market it torched it completely", he added.

Demonstrators then moved towards the police station where they called for "freedom" and chanted "the people want the fall of the regime".

Protests in Dongola, 500 kilometres north of Khartoum, "started with university students who were joined by others when they reached the city centre", an eyewitness told AFP by phone.

"They attacked the headquarters of the NCP and set it ablaze," the witness said.

In the city of Atbara, around 400 kilometres east of Khartoum, police fired tear gas to disperse protesters just hours after authorities imposed a curfew on the city because demonstrators had torched its NCP headquarters.

"Some 1,500 demonstrators tried to enter the city of Atbara from (a suburb) calling for the fall of the regime," an eyewitness said.

"Riot police intercepted them and fired tear gas at them," the witness added.

The bread shortage has hit Sudan's cities for the past three weeks, including the capital.

In the past year, the cost of some commodities has more than doubled in Sudan, where inflation is running at close to 70 percent and the pound has plunged in value.

Sporadic protests broke out in January this year over the rising cost of food, but they were soon brought under control with the arrest of opposition leaders and activists.

Sudan had significant oil reserves until South Sudan gained independence in 2011, and the north-south split saw the country lose three quarters of its reserves.

AFP