Kampala - A Ugandan rebel leader accused of killing hundreds of civilians was charged in court Wednesday with crimes against humanity and mass murder, a police spokesperson said.Jamil Mukulu, leader of the Allied Democratic Forces (ADF), was arrested in neighbouring Tanzania in April, before being extradited to Uganda earlier this month.The ADF is a Ugandan Islamist militia based in neighbouring Democratic Republic of Congo, with alleged links to al-Qaeda."He faces charges of mass murder and crimes against humanity," police spokesperson Fred Enanga told AFP, adding he also faced treason charges. "He was charged with two of his accomplices and the court is starting to hear the case."Mukulu appeared in court under heavy security in the town of Jinja, some 85km east of the capital Kampala, along with two other men accused of being ADF members.Journalists were barred from the court during the hearing, but were allowed to photograph the suspects.The ADF rebels launched an insurgency in Uganda against President Yoweri Museveni in the mid-1990s and later established bases on the Congolese side of the border.The ADF are accused of looting, the forced enlistment of child soldiers and illegal trade in tropical timber.Shabaab and al-QaedaStarting the mid-2000s the rebels began striking at the army and civilians, after authorities started to try to run them out of DR Congo.The rebels are accused of murdering - primarily with machetes and farming tools - hundreds of people in a string of massacres.The United States listed the ADF as a terrorist organisation in 2001, and Uganda's government accuses it of links to Somalia's Shabaab and to al-Qaeda. While no clear ties between the ADF and jihadist movements have been uncovered, the deputy UN peacekeeping chief in DR Congo, General Jean Baillaud, said earlier this month they had a "terrorist aspect" that could draw them closer to African jihadist movements.A UN report in May said the ADF had committed "systematic and extremely brutal" attacks in the last three months of 2014 that could constitute war crimes and crimes against humanity.