Women and children rallied quietly outside Sudan's state security headquarters Thursday calling for the release of prisoners held in a crackdown after protests over fuel price hikes, an AFP reporter said.
The crowd of around 45 carried photographs of the detainees, including social media activist Dalia El Roubi and Amal Habani, a journalist with Al-Khartoum newspaper, the reporter said.
Children held signs reading "Freedom for my mum" while others called for "justice".
Demonstrators gave security officers a memorandum asking for immediate release of the prisoners, and then they peacefully left the area, the reporter said.
Roubi, an employee of the World Bank in Khartoum, was taken from her home on Monday. Her husband Abdelrahman Elmahdi told AFP he still had no news about her on Thursday.
He and the couple's 13-year-old daughter attended the demonstration.
"They didn't try to disperse us," Elmahdi told AFP. "I think we got our message across."
Sudan's government says it has arrested about 700 "criminals" after last week's protests.
But rights watchdog Amnesty International said Wednesday that "reports from journalists, members of opposition parties, activists, and family members indicate that the figures are much higher".
It said security forces were believed to have killed more than 200 protesters, many with gunshot wounds to the head and chest.
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 during President Omar al-Bashir's 24-year rule.
The government said it had to intervene last week when crowds turned violent, attacking petrol stations and police facilities.