AN Australian and a Cambodian have been killed in an explosion which also injured another Australian during a military training exercise in Cambodia.

The Australians are understood to be military trainers and bomb experts and two others wounded on Thursday in Kampong Speu province, 50km west of the capital, were Cambodian soldiers, ThePhnom Penn Post reports.

It reported the blast happened at a shooting range within the base of an armoured vehicle unit in Phnom Sruoch district.

“We don’t know what happened yet, all we know is that there was an explosion,” said provincial police chief Sam Samoun, adding that the two Australians were in their 40s and that Cambodian soldiers made up the rest of the victims.

Their names have not yet been released.

A spokesman for Australia’s Department of Foreign Affairs said the department is providing consular assistance to the family of the Australian man killed and the Australian injured.

“Due to privacy obligations we are unable to provide further information,” they said.

Kampong Speu Provincial Governor Vy Samnang said it was believed the casualties were shooting at targets about 2pm (6pm AEDT) on Thursday when they noticed something on the ground.

“He said they went to pick up the object, a Russian-made bomb, which then exploded,” The Phnom Penn Post reported.

Samnang said the two Australians were bomb experts while the ABC has reported they are military trainers.

Kampong Speu Provincial Hospital health department director O Vann Then said the three wounded people had received “light injuries” to their hands.

“The body of the Cambodian soldier has already been taken out by family, while the Australian body is still at the hospital waiting to be taken by the Australian Embassy,” Mr Vann Then said.

The army is also investigating the blast, said defence ministry spokesman Chhum Sucheat.