Uganda's army has killed six fighters from an Islamic State-linked group that shot dead a honeymooning couple and their guide in a national park two weeks ago, the military said on Wednesday.

The army said its soldiers also captured a commander from the militant Allied Democratic Forces (ADF) which on October 17 murdered David and Celia Barlow and their Ugandan guide Eric Ayai in Queen Elizabeth National Park near the border with Democratic Republic of Congo.

Celia Barlow (nee Geyer) was South African and her new husband was British.

The army killed the ADF fighters and captured the commander, known by his nickname Njovu, during a night-time operation, Maj-Gen Dick Prit Olum said in a video statement.

"ADF terrorists whom we have been tracking down since the attack on tourists were finally got and a number of them were killed last night on Lake Edward," Ugandan military deputy spokesperson Deo Akiiki said earlier.

"The operation is still on to finish all the splinter groups of ADF," he added.

The ADF began as a movement opposing the Ugandan government in the early 1990s. After being routed by the army, it fled into Congo and got involved in the smuggling of timber, gold and agricultural products.

It pledged allegiance to Islamic State four years ago.

A day after the ambush, Islamic State claimed responsibility on its Telegram channel.

Reuters