A 21-year-old Australian soldier and an Afghanistan interpreter have been killed in Afghanistan overnight, the Australian Defense Force confirmed on Sunday.

According to Defense Force Chief Angus Houston, the incident happened around 10:30 p.m. (AEDT) on Saturday night during an un- partnered patrol in an area to the south-east of patrol base Wali.

Air Chief Marshal Houston said Sapper Jamie Larcombe, 21, and another Afghanistan interpreter were killed from a coordinated insurgent attack employing machine gun and small arms fire.

He said both men were shot and unable to be revived, despite the best efforts of their comrades.

"Unfortunately the soldier and interpreter showed no signs of life despite best efforts," he said in a statement released on Sunday.

"He was also a loyal friend who had a good sense of humor but wasn't interested in being the centre of attention," he said.

Sapper Larcombe is survived by his parents, three younger sisters and his girlfriend.

Twenty-three Australian soldiers have now been killed since Australia sent troops to Afghanistan in 2001.

Another Australian soldier, Corporal Richard Edward Atkinson was killed by a roadside bomb in Afghanistan earlier this month.