A British aid worker was shot and killed when rebels from Uganda's notorious Lord's Resistance Army (LRA) ambushed him while on his way to a southern Sudanese town over the weekend, the Ugandan army said.

Collin Lee, 67, who worked for International Aid Services and his wife and driver were heading from Uganda to the Sudanese town of Yei on Saturday when they were attacked about 12 kilometres (7.5 miles) from the border between Bazi and Molobo trading posts.

His wife and driver were injured in the incident which was carried out by 12 rebels.

"The rebels ambushed their Land Cruiser vehicle, burning it before they temporarily abducted Collin and the wife," army spokesman Captain Paddy Ankunda told AFP in Kampala.

Ankunda explained that the rebels shot at Lee and his wife after realising that soldiers from Uganda and Sudan People's Liberatiom Movement/Army (SPLM/A) were pursuing them.

Lee died five minutes after the trio were rescued, but his wife and driver were rushed to Arua hospital in northern Uganda.

The rebels are believed to have fled to eastern Democratic Republic of Congo, the army said.

In October, LRA rebels shot and killed two aid workers and wounded four others in separate ambushes in northern Uganda, prompting humanitarian groups to scale down operations in the impoverished and war-ravaged region.

A spate of attacks followed the issue last month by the International Criminal Court of arrest warrants for five top LRA leaders while governments in the region stepped up efforts to hunt down the group.

Tens of thousands of people have been killed and more than 1.6 million displaced in northern Uganda since the LRA took leadership of a regional rebellion against Kampala in 1988.