An LRA rebel keep vigil at Ri-kwangba near Garamba forest April 10, 2008. (Getty)

In an update released on Monday, the Geneva-based Small Arms Survey group said a verification team led by the AU special envoy for LRA issues Retired General Jackson Tuwei visited Khartoum on 12–15 September 2015.

"The AU delegates met with various Sudanese military and civilian officials who denied the presence of the LRA and Kony in Kafia Kingi but assured the AU of their full cooperation, including facilitating a future joint visit to Kafia Kingi," said the report.

The report however didn’t explain if the AU team paid a visit to the contested areas of Kafia Kingi which lies near the border with the Central African Republic (CAR) and South Sudan.

Following accusations by Ugandan government and reports by advocacy groups, Khartoum, which accuses Kampala of supporting Sudanese rebels, in May 2015 invited the African Union to send a fact finding mission to investigate these claims.

Defector rebels said the LRA fighters bring ivory from the Democratic Republic of Congo (DRC) to the Sudan’s controlled area of Kafia Kingi via eastern CAR. "Ivory is reportedly also exchanged for food, uniforms, and ammunition with Sudanese merchants likely connected" to Sudanese army, says the report.

Ugandan president Yoweri Museveni was last September in to Khartoum to discuss ways to facilitate the implementation of peace in South Sudan and to meet the former South Sudanese vice-president Riek Machar .

The visit also discussed the issue of rebel groups and the two countries agreed to resume discussions on the matter. Khartoum recently admitted that the Sudanese rebel leaders are no longer present in Uganda.

The South Sudanese army last month said it forces clashed with the LRA in Wunduruba areas, Central Equatoria state, but the Small Arms Survey group confirmed statements by the rebel SPLM-IO that the fighting of 15 September was in fact between the South Sudanese warring parties.

The existence of rebel groups and armed gangs in the whole central Africa region seemingly facilitates the activities of the Ugandan rebels who used to abduct and enrol children in their group.

LRA fighters murdered, raped, and kidnapped thousands of men, women, and children in the region. Seen as danger for peace and stability in the region the Obama administration in October 2011decided to send 100 Special Forces advisors to the African Union Regional Task Force.