KAMPALA — The African Union has taken control of a regional force hunting brutal rebel chief Joseph Kony across the central African jungles, an AU force commander said Wednesday.

"The AU now is in charge of the operations against the Lord's Resistance Army," Dick Olum, the Ugandan commander of the AU, told AFP.

The Ugandan army -- backed by around 100 US special forces troops -- has been spearheading regional efforts targeting Kony in a vast area where the borders of Central African Republic, Democratic Republic of Congo and South Sudan meet.

Olum said that the Ugandan military on Tuesday handed over command of some 2,000 troops to the AU at a ceremony at their base in Nzara, South Sudan.

He said that a further 500 South Sudanese troops have been placed under AU control awaiting deployment with another 150 Central African troops also handed over.

200 more troops are expected to join the force. Olum however said that the Congolese army was yet to contribute its quota of troops.

In March the AU announced intentions of establishing a 5,000-strong regional force to track LRA rebels in the area but the proposal was set back by funding and logistical delays.

"I am not very sure whether we shall realise the entire 5,000 strong force but at least we are above 50 percent," Olum said, adding that only the United States and the European Union had "so far done something" to back the force.

Kony's rebels have fought a 25-year insurgency against the Ugandan government and are notorious for a grim campaign of rape, mutilation and murder, kidnapping boys to serve as child soldiers and girls to act as sex slaves.

Since Uganda launched a raid on Kony's bases in neighbouring DR Congo in late 2008, the hunt for the elusive rebel chief has been hampered by friction among the regional armies.