Dozens of protesters chanted anti-government slogans as they left a major mosque following Friday prayers in Omdurman, near the Sudanese capital of Khartoum, a Reuters witness said.
The gathering was quickly dispersed after security forces fired teargas at the crowd
The protest was significantly smaller than other demonstrations seen in Sudan in recent weeks, triggered by price increases and shortages of cash and fuel following months of deteriorating economic conditions.
Organizers have urged protesters to march toward the presidential palace in Khartoum on Sunday, when larger numbers are expected to take to the streets.
Friday's protesters, mainly young men, chanted "peaceful, peaceful" and "step down, step down," as they called for a change in government.
Many protesters during the past two weeks have called for an end to the rule of President Omar al-Bashir.
The protests represent the most persistent opposition Bashir has faced since he took power in an Islamist-backed coup nearly 30 years ago. The demonstrations are more widespread and sustained than bouts of unrest in September 2013 and January 2018.
Security forces have fired live ammunition as well as tear gas and stun grenades at protesters, witnesses say. They have also detained some protesters and opposition figures.
Officials have acknowledged 19 deaths in the demonstrations. Amnesty International said last week it had credible reports that 37 protesters had been killed by bullets fired by security forces.
Bashir and the head of Sudan’s National Intelligence and Security Service have called for restraint in the response to the protests, which officials have blamed on infiltrators.