Ugandan soldiers hunting Lord's Resistance Army group leader Joseph Kony have killed one of his key bodyguards who earned notoriety for the abduction of children, according to an army spokesman.

The man, known as Brigadier Binani, was killed on Friday in a clash with Ugandan troops in the dense jungles of eastern Central African Republic close to the border with South Sudan, Felix Kulayigye, the spokesman, said.

"We got intelligence that the group was there and the squads were inserted to pursue them," Kulayigye said, adding that the clash took place about 280km north of the remote settlement of Djema.

In addition to being a Kony bodyguard, Binani was in charge of food collection as well as child abduction for the rebel group, but may not have been recently operating close to Kony, Kulayigye said.

The Ugandan army - backed by around 100 US special forces troops - is spearheading the hunt for Kony in a vast area of sparsely populated jungle.

Violent campaign

Believed to now number around 250 fighters, the LRA has waged a 25-year violent campaign against the Ugandan government, becoming infamous for mutilating victims and seizing children to use as sex slaves and porters.

Kony, a self-styled mystic leader who at one time wanted to rule Uganda according to the Bible's Ten Commandments, fled northern Uganda in 2005, roaming first the lawless parts of South Sudan, then the isolated northeastern tip of Congo.

The International Criminal Court at The Hague has issued arrest warrants for Kony and his top commanders for crimes against humanity and war crimes.

In December 2008, Uganda launched Operation Lightning Thunder against the LRA, dispersing the fighters and pushing them north into the jungles of Central African Republic where they survived on foraged and stolen food.

A video about Kony by a US filmmaker posted on YouTube last year attracted tens of millions of views, raising the international profile of the manhunt.