The move was ordered on Sunday by President Omar al-Bashir, his aide said.
“We will continue to eradicate the reasons behind the protests and arrests,” Abdulrahman al-Sadiq said on Sunday night.
Among those released were several high-ranking members of the National Umma Party – one of the most prominent opposition parties in Sudan – including the movement’s vice president and secretary-general.
Amal Habani, a women’s rights defender, was also freed.
The development comes several days after the American embassy in the Sudanese capital, Khartoum, said it was “deeply concerned” by the arrest campaign against “hundreds of political leaders, activists and ordinary citizens, many of whom are being held in inhumane and degrading conditions, and without access to lawyers or family”.
The embassies of the European Union also called on the Sudanese government to free the detainees last month.
The country witnessed widespread demonstrations, called “bread protests”, at the start of 2018, when the government decided to cut subsidies and stop importing wheat from overseas.
The opposition had said more than 300 people were arrested in the wave of protests. Several people participating in the rallies were killed when the government responded with force.
The decision was part of a raft of austerity measures passed by the Sudanese government within the country’s 2018 budget, which seeks to address the spiralling inflation rate.
The government’s austerity policies have sparked sporadic protests in recent years.
According to rights group Amnesty International, some 185 people were killed in 2013 during demonstrations against a rise in fuel prices.
When the protests erupted, the country’s finance minister said black-market manipulation is the reason behind the recent spike, but analysts blame the government’s policies.