Sudanese security forces fired tear gas and stun grenades on Friday at 300-400 protesters leaving a mosque in Omdurman, near the Khartoum.
Activists had called for large protests to take place following weekly Muslim prayers on Friday, Reuters reported.
Sudan has been rocked by more than a week of anti-government protests sparked by rising prices, shortages of basic commodities and a cash crisis.
At least 19 people have died during the protests, including two military personnel, according to official figures.
According to Reuters, Sudan was shaken in January by demonstrations triggered by high bread prices. Authorities have shuttered schools and declared curfews
and states of emergency in several regions, and residents say police have used tear gas and sometimes live ammunition against demonstrators.
Putting the death toll at 19, Sudan's information minister on Thursday blamed some of the deaths on clashes between shopowners and what he described as "looters".
He said 219 civilians and 187 members of the security forces had been wounded.
