RIYADH // In its eight-year counter-terrorism campaign against al Qa'eda, the Saudi government has detained 11,527 people for suspected terrorist-related activities, but released just over half - 5,831 - after they were found innocent. In its first full accounting of security detainees held in connection with the government's domestic battle against al Qa'eda, the Saudi Ministry of Interior announced on Saturday that 1,612 of those still detained are serving prison sentences. Another 603 are being tried in ongoing proceedings; 934 are awaiting the start of their trials; and 616 are still being investigated, the ministry said. In the cases of 1,931 other detainees, the authorities have completed their investigations and the results are being forwarded to prosecutors for a decision on whether to take the cases to trial or not, the ministry stated. The disclosures come shortly after several small demonstrations outside the Interior Ministry in Riyadh by female and male relatives of detainees. They were complaining that family members are held for years without being charged or brought to trial. On another occasion, about 200 relatives of detained persons spent a day inside the ministry demanding to see the interior minister, Prince Nayef bin Abdul Aziz, according to one of the relatives who was there. Interior ministry spokesman Gen Mansour al Turki said the information was released in order to give an accurate accounting of the number of people detained. A second purpose, he said, was to demonstrate that "not everyone who is arrested will stay forever [in prison]. We have released more than 50 per cent". In May 2003, al Qa'eda launched a violent campaign to destabilise the kingdom, targeting residential compounds, Saudi policemen, foreign embassies and vital installations, often with suicide bombers. The last major attack was in February 2006, when extremists attempted to attack the world's largest oil processing facility at Abqaiq. In 2008, the interior minister, Prince Nayef, who also serves as second deputy prime minister, disclosed that militants had carried out more than 30 attacks, killing 164 people, including 74 security officials, and injuring 657 police and 439 civilians. He added that more than 160 other "terrorist operations" had been foiled. Although Prince Nayef had promised that all detainees would be brought to trial, information has been scarce about the number of people prosecuted, what offences have been involved, or the length of their sentences. In July 2009, the government disclosed that up to then, 330 people had been tried on terrorist charges, with seven acquitted. Of the 323 convicted, a number which included 41 non-Saudis, 13 had been sentenced to prison terms of more than 20 years. One was given the death sentence. These earlier figures are included in the statistics released Saturday, Mr al Turki said. Trials are held in Riyadh in a special court for terrorism charges. Human-rights organisations and some local lawyers have criticised the proceedings for being closed to the public and for not giving defendants due process. Family members have told human-rights groups that defendants are not allowed to have their own lawyers. The interior ministry also said on Saturday that it has given 32 million riyals (Dh31.3m) in compensation to 486 detainees because they spent more time in detention than their allotted sentences. Mr al Turki acknowledged that some detainees who have completed their sentences are still held. He said that a committee headed by a judge had determined that these detainees were still "dangerous" to society. He did not have a figure on how many are in that situation. The spokesman also said that the ministry has spent 529 m riyals on stipends to the families of detainees, whether they are convicted or not. He said this financial support was necessary because "if we leave them, they will be lost … and somebody might take advantage of that and might recruit their kids".