Amnesty International has urged the Sudanese authorities to end their crackdown on freedom of expression following the arrest of four employees of an opposition newspaper in a late night raid by security forces. Abuzar Al Amin, Nagi Dahab, Ashraf Abdelaziz, and Abu Baker Al Sammani were arrested on Saturday in Khartoum – the same day as opposition leader Hassan Al Turabi – by the National Intelligence and Security Services (NISS). The four men all work for Rai Al Shaab, a Sudanese opposition newspaper closely affiliated with Al Turabi’s Popular Congress Party. The newspaper offices were also shut down by the NISS and remain closed. “The Sudanese authorities must stop trying to silence opposition by using the security forces to crack down on freedom of expression,” said Erwin van der Borght, Amnesty International’s Africa Director. “These four men were arrested solely for the peaceful exercise of their right to freedom of expression and opinion. We are calling for their immediate and unconditional release.” No charges have yet been brought against any of the employees whose whereabouts remain unknown. Amnesty International said it is concerned that they may be tortured or otherwise ill-treated while in custody. NISS agents retain sweeping powers under the 2010 National Security Act, passed by the Sudanese National Assembly in December 2009. “These arrests are another example of the arbitrary use of the extensive powers granted to members of the security forces in Sudan. NISS agents have constantly harassed students, journalists and human rights defenders who have exercised their peaceful right to freedom of expression,” said Erwin van der Borght. “Freedom of expression will continue to suffer in Sudan until repressive laws such as the 2010 National Security Act are reformed.” Amnesty International has called on the government of Sudan to curb the NISS’s extensive powers such as arrest and detention without judicial oversight, and search and seizure.It is unclear exactly what prompted the arrest of Al Turabi and the four staff members of Rai Al Shaab. However, some reports said it was linked to an interview Al Turabi gave shortly before his arrest to another Sudanese newspaper in which he claimed that the April 2010 general elections were rigged.The legal grounds on which Rai Al Shaab was closed down and its staff members arrested remain unknown.