SAS troops are believed to have killed a group of insurgents responsible for the death of a New Zealand soldier in Afghanistan.

Lieutenant Tim O'Donnell, 28, died on patrol in August last year, and was NZ's first war fatality in a decade.

Two other soldiers and an Afghan interpreter were wounded.

The ambush took place in the northeast province of Bamiyan and it was believed the group who attacked his convoy was from neighbouring Baghlan.

TVNZ reported the SAS launched an attack in Baghlan about two weeks later, in which nine insurgents died.

Defence Minister Wayne Mapp said the operation was carried out to "secure" the area and denied it was a revenge killing.

He said no civilians died in the attack.

O'Donnell served in the army for five years, and was part of the Provincial Reconstruction Team of about 140 NZ troops which carried out a mixture of aid work and military patrols in Bamiyan.

He was also the youngest ever officer to be recognised with a Distinguished Service Decoration for a notable act of valour in East Timor.