Some of the demonstrators closed a bridge linking Khartoum to a marine neighborhood, causing huge traffic jams, AFP quoted witnesses.
Thousands participated on Saturday in the biggest anti-government rally since the protest movement broke out in December, during which they first arrived at the headquarters of the army's general headquarters.
The army did not intervene but riot police deployed near fired tear gas at demonstrators to disperse them, while some threw stones, witnesses said.
The Central Doctors' Committee in Sudan announced the deaths of five people during the demonstrations in the Sudanese capital Khartoum and other cities yesterday.
Officials said 32 people had been killed in violence linked to the protests since it began on December 19 following the government's decision to raise the price of bread three times. Human Rights Watch, for its part, estimates the death toll at 51, including children and workers in the health sector.