Sudanese authorities said more than 80 political prisoners would be released from jails in Khartoum, a week after the country appointed a new security chief.
A Reuters reporter said he saw about 40 prisoners released from the main prison by Sunday evening and some prominent opposition leaders were still held there.
A presidential adviser earlier said in a statement President Omar Hassan al-Bashir ordered more than 80 political detainees released.
All were arrested last month after protests about high prices and tough economic conditions that turned violent.
Families celebrated in front of the jails on Sunday, with some chanting “freedom, freedom” and singing national songs.
A group of people started a sit-in outside one prison, saying they would not leave until all political prisoners were freed.
The United States in October lifted 20-year-old sanctions on Sudan, prompting calls from the International Monetary Fund for the country to float its currency among other measures it said could help the economy recover.
Sudan rejected floating the currency but devalued it in January and cut wheat subsidies, sending the pound’s value plummeting on the black market and doubling bread prices that led to January’s demonstrations.
The weak black market rate of the pound forced authorities to slash the rate at which banks trade dollars.
Sudan’s economy has been struggling since the south seceded in 2011, taking with it three-quarters of its oil output.
Opposition groups accused the president of jailing dissidents and censoring the media.
Bashir has remained in power for more than a quarter of a century, weathering rebellions, economic crisis and an indictment by the International Criminal Court on suspicion of orchestrating war crimes in Sudan’s Darfur region.