Sudan's president Omar al-Bashir announced on Thursday he has freed Islamic leader Hassan al-Turabi; detained last year in connection with an alleged coup plot.
Bashir also said that he will release all political prisoners and that his government will undertake other reform measures.
"(I announce) the release of all political detainees," the Sudanese President said in a speech he delivered on Thursday, marking the 16th anniversary of his coup.
It was not immediately clear how many detainees would leave jail and whether any had come out already.
Hundreds of supporters chanting "Allaho Akbar"; "God is great" welcomed Al Turabi, a former ally of President Omar Hassan al-Bashir, to his Popular Congress party headquarters in the Sudanese capital.
The political climate in Khartoum has majorly improved since the signing of agreement in January between the government and southern rebels, that ended more than 20 years of civil war.
Hassan Al Turabi, an ideologue well known throughout the Muslim world, has spent the past five years in detention.
His Popular National Congress confirmed news of his release on Thursday.
Mr. Al Turabi, once a close colleague of President Al Bashir, has been detained since March last year, for his alleged role in what the government says was a foiled coup attempt in September 2003.
"He has been released from the place he was being held and he is on his way to the headquarters of the party," his secretary Awad Babiker said.
Mr. Al Bashir also said that Sudan’s state of emergency will be lifted when an interim constitution was adopted and a unity government installed, expected early next month.