25 May 2011 :

Thirteen members of Al-Qaeda in the Islamic Maghreb, including eight on death row, were moved from the Mauritania capital's central jail to a secret location, security sources said. Security sources and relatives of the prisoners said they were transferred on May 22 night by armed, masked soldiers, without explanation.
Authorities refused to comment.
Among the eight sentenced to death, three had been found guilty of involvement in the murders of four French tourists in Aleg in south Mauritania in December 2007.
The other five are serving sentences ranging from ten to 15 years.
Relatives of the prisoners staged a sit-in outside the prison on May 22 and 23, demanding information on the whereabouts of their family members.
Local media reported that "prisoners considered to be dangerous were taken by helicopter to a military prison in the north of the country."