An Afghan soldier opened fired and killed four people including three NATO soldiers and their local interpreter in Uruzgan province 370 km south of capital city Kabul on Saturday, Afghan army commander in the southern region General Abdul Hamid Wardak said.

"The tragic incident happened during training time in provincial capital Trinkot city this morning when Afghan soldiers were receiving training but unfortunately suddenly a soldier opened fire killing three Australian troopers and a local interpreter," Wardak told Xinhua.

Five more people including an Afghan soldier sustained injuries in the firing, the official confirmed without giving more details.

However, he said investigation has been initiated into the case, adding complete details would be made public after completion of investigation.

This is not the first time that rogue Afghan soldiers kill NATO troopers in Afghanistan. A rogue Afghan pilot opened fire on April 27 this year killing nine people including eight American trainees at Kabul military airport.