Neighbourhood resistance committees called the protests despite an agreement last week that reinstated civilian Prime Minister Abdalla Hamdok and brought the release of most top politicians detained since the coup.
The Oct. 25 takeover ended a partnership with civilian political groups since the topping of Omar al-Bashir in 2019 and drew condemnation from Western powers who have suspended aid.
The committees and political parties have rejected the deal, but Hamdok said it would bring the release of dozens of detainees, end a crackdown on protesters that has seen 42 people die, and preserve billions in foreign aid.
Wagdi Salih, popular leader of a controversial anti-corruption taskforce, was released late on Monday night, according to his Twitter account and sources close to him.
However, Salih and others including still-detained politicians Ibrahim al-Sheikh and Ismail al-Tag, face charges of inciting the armed forces, lawyer Moiz Hadra said.