The arrest of Caesar Achellam is a major victory for multi-national forces combating the LRA across central Africa.

The operations center in the Central African Republic, shared by the Ugandan military and American Special Forces, has posted Achellam's photograph to a wall, next to the other top targets in the LRA, including rebel leader Joseph Kony.

The Reuters news agency quoted Ugandan military spokesman Felix Kulaigye describing Achellam as “a big fish.”

The military says he was arrested in the Central African Republic, one of the countries where the LRA is known to operate. The group once numbered in the thousands, but U.S. and Ugandan military officials believe there are only a few hundred fighters left.

They travel in small groups - Achellam was with about 30 other rebels when he was caught - and move freely through the forests of central Africa, living off the land and stealing from villages.

The group is notorious for kidnapping children to serve as soldiers, porters and sex slaves. Thousands have been abducted since the LRA began its insurgency in Uganda more than 25 years ago.

Last year, U.S. President Barack Obama authorized the deployment of about 100 U.S. Special Forces to advise and assist regional militaries. In total, about 2,500 soldiers are engaged in the operation to defeat the LRA.

The African Union is preparing to take control of the international military campaign and hopes to double the number of troops on the ground.

U.S. commanders say intelligence gathering is key to defeating the LRA. But, the group is difficult to track. Its members do not use mobile phones, and the smaller subgroups only rarely meet to exchange supplies and information.

The campaign against the LRA and Joseph Kony gained international attention in March when a video about Kony by the U.S. group Invisible Children became wildly successful on YouTube, gaining tens of millions of views in a matter of days.

Meantime, Kony's whereabouts are still unknown. Ugandan military officials have said recent intelligence suggested he was in the southern Darfur region of Sudan. More recently, officials have said he is moving around in the Central African Republic.