Sudan said on Tuesday it has freed most of the hundreds of people detained after protests sparked by fuel price hikes in late September, when dozens were killed.
"Starting from yesterday anyone who has not actually committed any sort of crime or destruction or killing has been released," with more expected to be freed on Wednesday, Information Minister Ahmed Bilal Osman told AFP.
The government announced last week it had detained about 700 "criminals" after the protests which followed the government's September 23 decision to cut fuel subsidies.
Thousands took to the streets in the worst urban unrest of President Omar al-Bashir's 24-year rule.
Osman said he expects "around about 200" to face a trial.
"Everybody that committed a crime will go to court," he said. "If there is no case against him he will be released."
Bashir on Sunday ordered several female detainees to be freed including Dalia El Roubi, an activist and an employee of the World Bank in Khartoum.
Roubi, who was held for seven days without charge, told AFP on Tuesday that activists have the names of more than 200 prisoners but she saw "hundreds" of others during her detention by the National Intelligence and Security Service (NISS).
"There's a lot of people that no one knows their names," she said.
Among those who have been identified are two employees of the United Nations Development Programme, Roubi said.
The UNDP spokesman could not be reached on Tuesday night and Osman, the minister, said he was not sure if any UN staffers were held.
Osman added that "there might be" people from neighbouring countries, which he did not identify, among those who were detained.
The African Centre for Justice and Peace Studies, a human rights watchdog, said Saturday more than 800 people had been arrested throughout the country by police and the NISS.
The prisoners included political activists, opposition party members and human rights defenders, the watchdog said, adding the exact number of detentions was unknown.
Trials for some of the accused have already begun and the case of 16 continued on Tuesday in Khartoum's impoverished Haj Yousef district.
Thirty-five people initially appeared on charges of vandalism and causing a disturbance but a judge acquitted 19 for lack of evidence.
The other 16 include eight youths under the age of 17, said Mutasim al-Haj, one of their lawyers, who added that a dozen witnesses testified for the defence on Tuesday.
"They said these people were not arrested during a demonstration. Nor were they arrested during the stoning or burning of police stations," Haj said.
They were picked up "far away" from the alleged crime scenes, according to defence testimony, the lawyer added.
A judge is expected to give his verdict on Thursday after further defence evidence, Haj said.
Security forces were believed to have killed more than 200 protesters, many of whom were shot in the head or chest, Amnesty International said.
Authorities have reported 34 deaths from the unrest.
The government said it had to intervene when crowds turned violent, attacking petrol stations and police.
Osman said two or three police were killed and "maybe more than three" NISS members, while more than 100 others were injured.