The US government has released another prisoner from the Guantanamo prison camp. Ghassan al Sharbi was transferred to his country of origin, Saudi Arabia, on Wednesday, the Pentagon said. According to information from the human rights organization Human Rights Watch, 48-year-old al Sharbi was arrested on March 28, 2002 in Faisalabad, Pakistan. Three months later he was taken to Guantanamo, as the New York Times reported.

The qualified engineer was suspected of having built bombs for the terrorist militia al-Qaeda. However, he was never convicted. For the United States, al Sharbi was of particular interest because he attended a flight school in Phoenix, Arizona, with two of the attackers of September 11, 2001.

According to the Pentagon, after al Sharbi’s release there are now 31 prisoners in the controversial prison camp in Cuba. At times almost 800 people were imprisoned there. The camp was set up under Republican President George W. Bush after the September 11, 2001 terrorist attacks in the United States to hold suspected Islamist terrorists without trial. Human rights organizations have long called for the closure.