Biniam Solomon, now in his early 60s, was arrested in the capital, Asmara, in 2011 but was never tried. The reasons for his continued imprisonment were not made clear. Known by his pen name Cobra, Biniam gained fame for his critical and witty cartoons tackling political and social issues. The authorities have not said why he was set free but it is the latest in a string of similar releases. Nevertheless thousands remain in prison, incommunicado and without trial, in a country long criticized for alleged human rights abuses. During his 15 years in detention, Biniam had no contact with his family, and received only occasional medical treatment. According to a relative, he spent the latter part of his detention in Asmara's "crime investigation" prison. It is widely reported to hold political and conscientious objectors under harsh conditions. Despite losing an arm in childhood, Biniam pursued a career as an artist and produced a substantial body of work. To supplement his income, he was also employed as a physics teacher at a secondary school in Asmara. His cartoons were published in several Eritrean newspapers in the four years from 1997. (BBC)