Sudanese security forces fired tear gas to disperse protesters in Khartoum on Saturday as demonstrators once again took to the streets in the country's capital and elsewhere to denounce the October military coup.
Authorities had warned protesters against approaching "sovereign and strategic" sites in central Khartoum - a reference to main government buildings and key institutions.
The city's Security Committee said Sudanese forces would "deal with chaos and violations".
The marches started in different locations, from where the protesters meant to converge on the presidential palace.
Security forces used tear gas to disperse those attempting to approach the palace, said activist Nazim Sirag. There were no immediate reports of injuries.
Rallies were also underway in other cities, including Wad Madani and Atbara.
Last weekend, security forces violently dispersed demonstrators when they attempted to stage a sit-in near the presidential palace. At least three protesters were killed.
United Nations envoy Volker Perthes urged security forces to "protect" the planned protests, and refrain from arresting people for simply wanting to take part in the demonstrations.