Amnesty International has urged the Sudanese authorities to release or charge eight Darfuri men and women who are reported to have been arrested and held incommunicado since last weekend, and who are believed to be at risk of torture.
According to reports by local activists and NGOs, a number of activists, some of whom have been monitoring the human rights situation in Darfur, are believed to have been arrested and detained by the National Intelligence and Security Services (NISS) in Khartoum between 30 October and 1 November.
The authorities have not yet acknowledged the arrests and the families of those taken have not had any news of their whereabouts or been given reasons for their arrests.
"The detention, torture and ill-treatment of human rights activists and journalists by the NISS occurs frequently in Sudan, particularly amongst Darfuris," said Erwin van der Borght, director of Amnesty International's Africa programme.
"The authorities must reveal the names and whereabouts of all those detained and either charge them with recognizable criminal offences or release them immediately.”
The recent arrests targeted Darfuris working for the Human Rights and Advocacy Network for Democracy (HAND), a coalition of grassroots organizations that publishes human rights reports on Darfur.
The arrests seem to have also targeted people believed to be working for Radio Dabanga, a Sudanese radio station that broadcasts news on the conflict in Darfur. Both organizations are thought to operate from the same office building in Khartoum.
In July 2010, the Amnesty International report, Agents of Fear: The National Security Service in Sudan documented human rights violations committed by the NISS and the clampdown on freedom of expression and association in Sudan that has seen human rights defenders, activists and journalists regularly detained for carrying out their work while others have been tortured or tried on politically motivated charges.
Under Sudan's National Security Act the NISS has extensive powers of arrest and detention. NISS agents are also granted immunity from prosecution for any act committed in the course of their work.
"Under these laws NISS members have been carrying out human rights violations without fear of being held to account," said Erwin van der Borght.
"The 2010 National Security Act must be reformed to remove these excessive powers from the NISS.
"The government must also act to ensure that human rights activists and journalists working in Sudan are not harassed and intimidated by the NISS for simply trying to do their jobs."