Sudanese President Omar Hassan al-Bashir has ordered the release of all political prisoners.
In a speech Monday at the opening of parliament, Mr. Bashir also said the government was committed to a "national dialogue" with all groups.
It was not immediately clear when and how many prisoners would be released.
The move comes as tensions begin to ease in Sudan after it reached an agreement last month with South Sudan to end hostilities and resume cross-border oil flows. The two neighbors came close to war a year ago.
Last week, Vice President Ali Osman Taha invited rebel groups to help prepare a new constitution.
Opposition parties and human rights groups welcomed the announcement.