The Department of Defence has confirmed four Australian special forces soldiers were wounded in an operation in Afghanistan last week.

Defence said one of the four suffered serious wounds in the incident on October 18, while the other three suffered only minor wounds while on operation in the Shah Wali Kot region of northern Kandahar province.

Three of the Special Operations Task Group soldiers suffered gunshot wounds and were evacuated by air for medical treatment, while the fourth suffered shrapnel wounds.

The statement said all four soldiers were expected to make full recoveries, and two would be flown back to Australia.

All four are currently receiving medical treatment and no further details can be disclosed due to "the soldiers' protected identities".

Defence said no other Afghan, Australian or ISAF soldiers were wounded in the action, and no civilians were injured.

Due to ongoing operations and security Defence said it delayed the release of information on the incident until today.

The latest incident brings to 56 the number of Australians wounded this year, with 156 wounded since 2001.

Twenty-one Australian troops have been killed since the war began.