Hundreds of men and women marched for "freedom" in the Sudanese capital on Friday despite the deployment of militia, troops and riot police, AFP correspondents reported.
One of the largest rallies occurred in the poor Shambat area of North Khartoum, where several hundred residents marched along the dirt roads between their houses.
They tried to make their way to a large lot but were blocked by uniformed security officers armed with rifles.
"A million martyrs for a new dawn," they called.
"Freedom! Freedom! Justice! Justice!"
They chanted: "The people want the fall of the regime," rallying cry of the 2011 Arab Spring revolts which toppled longtime rulers around the region.
Elsewhere, hundreds demonstrated outside a state security service building, a United Nations source said, adding there had been a number of other peaceful demonstrations.
The protests followed the main weekly Muslim prayers and came in spite of the roundup of hundreds of people after deadly demonstrations last week.
Authorities say 34 people died after petrol and diesel prices jumped on September 23 when the government cut fuel subsidies, sending thousands into the streets in the worst urban unrest of President Omar Al-Bashir's 24-year rule.
Amnesty International says security forces are believed to have killed more than 200 protesters, many with gunshot wounds to the head and chest.
The intensity of protests decreased markedly this week.