This image made from AP video shows Seif al-Islam Gadhafi, son of Libya's former dictator Moammar Gadhafi, inside a cage in a coutroom in Zintan, Libya, Thursday, Sept. A militia-run prison failed to transfer Gadhafi to a pre-trial hearing in Tripoli on Thursday, underscoring the central government's difficulty in asserting its authority since the end of the country's civil war. (AP Photo via AP video) This image made from AP video shows Seif al-Islam Gadhafi, son of Libya's former dictator Moammar Gadhafi, inside a cage in a courtroom in Zintan, Libya, Thursday, Sept. FILE - In this Feb. 25, 2011, file photo, Seif al-Islam Gadhafi, son of Libyan leader Moammar Gadhafi, speaks to the media at a press conference in a hotel in Tripoli, Libya. A militia-run prison failed to transfer Seif al-Islam to a court hearing in Tripoli on Thursday, Sept. 19, 2013, underscoring the central government's difficulty in asserting its authority nearly two years after the end of the country's civil war. TRIPOLI, Libya (AP) - The son of Libya's former dictator Moammar Gadhafi missed a court hearing Thursday after the militia holding him refused to send him to the capital, underscoring the continued weakness of the central government after the country's civil war. Seif al-Islam Gadhafi, the most prominent figure of his father's regime, appeared for a separate hearing instead in the western town of Zintan, where a militia has held him since the end of the war. Footage aired on state television showed the slim, bearded Gadhafi standing and sitting in a cage inside the courtroom, wearing a blue prison jump suit. A judge there adjourned Gadhafi's trial until Dec. 12 over a lack of evidence. Al-Seddik al-Sur of the state prosecutor's office told reporters Thursday that authorities have asked for "justification" as to why Gadhafi was not transferred from Zintan as planned. The Tripoli trial involves 38 former regime officials, including notorious spymaster Abdallah Senoussi, but only 36 were in attendance. In addition to Gadhafi, another unidentified defendant was not there. Thursday's hearing was to present the prosecutors' case to the judge who will then evaluate its merits and possibly order more investigations before setting the official charges. The charges are expected to revolve around the killings during the eight-month civil war in 2011. State television showed at least a dozen men sitting in blue prison suits in a row behind bars surrounded by baseball cap-wearing security guards in the Tripoli courtroom. The court itself otherwise appeared empty. A few dozen people protested outside the courthouse, mostly family members of those who died during the war as well as during the years of Moammar Gadhafi's rule. Women carried portraits of their dead sons while others plastered pictures of them on the building's fence. Seif al-Islam Gadhafi, the only member of the family to go on trial so far, faces charges from the Zintan militia that captured him as he was trying to flee south to Niger. International institutions and rights groups have criticized the trial conditions facing Gadhafi. "Our main concern is he is still being held by a militia in Zintan outside the authority of the state," said Hanan Salah, who follows the case for Human Rights Watch. She said the situation for Gadhafi was indicative of the shortcomings of justice in Libya in general, where due process is often not followed, lawyers have been intimidated and detention facilities are poorly supervised. In general, we have concerns over the facilities that are not under (the) full custody of the state. This is where we have documented serious abuses," she said, adding that Gadhafi has yet to see a lawyer for the Tripoli-based trial. He did have a lawyer for his future case in front of the International Criminal Court, but she was detained after her second meeting with him in Zintan on charges of trying to smuggle documents and a camera to him. Magda Mughrabi, a researcher for Amnesty International who met with Gadhafi on Sept. 9, described the refusal to give up Gadhafi as typical of the power struggle between the central government and the militias. She said it happens daily with other detainees. "Militias use valid arguments that this is driven by security considerations and that it is not safe to hand him to Tripoli," she told The Associated Press by telephone from London. It might be actually true in a sense but the wider problem is the fact that there is a weak government and different militias are using the security vacuum and current lawlessness in asserting their control to challenge the authority. Successive Libyan governments have failed to impose law and order in the country since rebel forces overthrew Moammar Gadhafi and killed him. Authorities instead rely on heavily armed militia groups, initially drawn from the rebellion, for security, although some began challenging the central government as it struggles with a transition to democracy. In his briefing to the Security Council on Monday, U.N. Libya representative Tarek Mitri warned of the increasing divisions in the country putting strain on its politics. He also warned about the treatment of prisoners. "The situation of many of the estimated 8,000 conflict-related detainees remains problematic," Mitri said. While the Ministry of Justice has reported a reduction in complaints, reports of deaths in custody torture and other forms of ill-treatment continue to be a source of concern. Gadhafi's son and the spy chief are wanted by the International Criminal Court on charges of murder and the persecution of civilians during the early days of the uprising. If convicted there, they would face a maximum sentence of life imprisonment. The ICC does not recognize the death penalty. This summer, judges from The Hague-based court ruled that Libya cannot give Gadhafi's son a fair trial and asked authorities to hand him over. Associated Press writer Maggie Michael in Cairo contributed to this report.