Uganda's military on Tuesday dismissed a United Nations (UN) report accusing it of using cluster bombs in the South Sudan town of Bor.

Ugandan Chief of Defense Forces General Edward Katumba Wamala told reporters here that, as a signatory to the Convention on Cluster Munitions, Uganda had banned the use of cluster munitions by its army, the Uganda People's Defense Forces (UPDF).

He said the UPDF was ready to cooperate with the African Union Commission of Inquiry, which is investigating war crimes in the South Sudan conflict.

"It's not the first time for us to cooperate with the international community in an investigation. We provided escorts to some investigative staff who came to find out whether there was a massacre in Bor. We have nothing to hide," Katumba said.

A U.N. Mission in South Sudan report says evidence has been found of the use of cluster munitions in Bor, which is under UPDF and South Sudan government forces control.

"The United Nations Mine Action Service found physical evidence of the use of cluster munitions in the Malek area, approximately 16 kilometres south of Bor," the May 8 report says.

Cluster munitions, which can be fired in various ways, explode in the air, with each cluster releasing about 150 bomblets over a wide area.

It is banned by the Convention on Cluster Munitions because of its potential to cause indiscriminate damage over a wide area and leave many unexploded bomblets on the ground.

Approximately 20 percent of the bomblets fail to explode, presenting a risk for years after.

While Uganda has signed the Convention on Cluster Munitions, South Sudan is not a party to it.