KAMPALA:   A Ugandan rebel leader blamed for slaughtering hundreds of civilians has been extradited to face trial in Kampala, a Ugandan government spokesman said Friday.

Tanzania announced in April police had arrested Jamil Mukulu, leader of the Allied Democratic Forces (ADF), after which Uganda requested he be sent to Kampala for trial.

"Fugitive ADF's Jamil Mukulu's long run with the law comes to an end," Ugandan government spokesman Ofwono Opondo said, confirming he "has been extradited to Uganda."

The ADF is a Ugandan Islamist militia based in neighbouring Democratic Republic of Congo, with alleged links to Al-Qaeda.

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.

They are accused of looting, the forced enlistment of child soldiers and illegal trade in tropical timber.

Starting 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.

Mukulu, believed to be 51, is wanted in Uganda for a range of crimes including terrorism and murder. The international police agency Interpol issued a warrant for his arrest at Uganda's request.

"Finally, Jamil Mukulu has been extradited to Uganda, justice will prevail," Ugandan military spokesman Paddy Ankunda added.

Rights groups said they welcomed the coming trial.

"His trial could be an opportunity for justice... for people in both Uganda and Congo, Mukulu's arrest marks a new chapter," said Maria Burnett from Human Rights Watch (HRW).

"It will now be up to Ugandan prosecutors to ensure a fair, meaningful judicial process in a timely way," she added.

The United States listed the ADF as a terrorist organisation in 2001, and Uganda's government accuses it of links to Somalia's Al-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.

Last December, UN troops launched a joint operation with the Congolese army against the ADF. While a degree of calm was restored, the intervention failed to bring a halt to the killings of civilians — mostly by machete.

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.