DAKAR (Reuters) - Kidnappings in Central Africa by the Lord’s Resistance Army (LRA) hit a six-year high in the first half of 2016 just as Uganda threatened to roll back its involvement in an operation to hunt down the rebels, monitoring groups said on Wednesday.

The LRA, a Ugandan rebellion headed by messianic leader Joseph Kony, abducted 498 civilians between January and June, according to a report by The Resolve and Invisible Children, two groups that track LRA violence.

Seventeen people were also killed during 122 attacks recorded during the period, nearly all of which occurred in northern Democratic Republic of Congo and eastern Central African Republic (CAR).

“The international community must do more to protect civilians in eastern CAR from the LRA and other armed groups,” Sean Poole, Director of International Programs at Invisible Children, said in a statement.

For the first time, two attacks were also reported in the Kafia Kingi enclave controlled by Sudan, where Kony is believed to have sought refuge.

Originally from northern Uganda, the LRA was driven out by a military offensive a decade ago and now roams a poorly policed area straddling the borders of Central African Republic, Democratic Republic of Congo and South Sudan.

The International Criminal Court has issued arrest warrants for Kony and other senior commanders of the LRA, which is notorious for mutilating civilians and kidnapping children for use as fighters and sex slaves.

The group was not well known outside Central Africa until KONY 2012, a social media campaign that raised international awareness about the reclusive warlord.

The U.S. military in March estimated that fewer than 200 LRA fighters remained, and a Uganda-dominated African Union regional task force has been hunting them down.

Most of Uganda’s 2,500 troops are operating in eastern Central African Republic with a smaller contingent based in South Sudan. Kampala said last month it planned to withdraw from CAR due to a lack of support from the international community.