Sudan's feared spy agency, the National Intelligence and Security Service, which used deadly force against pro-democracy protesters, has been renamed by the country's army ruler, the agency's chief said Monday.

The agency, widely known as NISS, launched a sweeping crackdown on street protests which erupted in December against now ousted leader Omar al-Bashir. 

NISS, a key tool of Bashir to repress dissent, will now be called General Intelligence Service (GIS), its chief Lieutenant General Abu Baker Mustafa said in a statement.

He said the name change follows a decree issued by the head of the country's ruling military council General Abdel Fattah al-Burhan.

The council took over after the military ousted Bashir in April and is now working with an alliance of protest and opposition groups on a power-sharing deal. 

"The change in the name comes at a time when the security apparatus is being restructured to keep pace with the political changes in the country," Mustafa said.

"The name change also reflects increased professionalism in the agency to help protect the country and national security."

During the ironfisted rule of Bashir, NISS oversaw repeated crackdowns on government opponents and the media.

Its agents frequently confiscated the entire print-runs of newspapers that criticised government policy or reported on anti-government protests.

When agents of NISS targeted anti-Bashir protesters, the crackdown left dozens dead, hundreds wounded and thousands arrested in the months-long protest campaign before the army ousted Bashir on April 11.

The crackdown was overseen by the former head of the agency, Salah Ghosh, who resigned from his post soon after Bashir's ouster. He was replaced by Mustafa.

Ghosh, had worked on and off for NISS ever since the 1989 coup that brought Bashir to power, according to Sudanese media.

He was credited with building NISS into one of the most important pillars of Bashir's regime.