The Australian Defence Force has begun a series of controversial exercises in East Timor involving Black Hawk helicopters firing live machine-gun rounds.

Advertisements warning of the exercises appeared in East Timorese newspapers last week.

Australian Black Hawk and New Zealand Iroquois helicopters attached to the International Stabilisation Force in East Timor are training in the Fatin Tiru firing area off the north coast.

The exercises are about 6km from the town of Liquica, the scene of a massacre by pro-Indonesian militias before East Timor's 1999 independence ballot.

The advertisements say the helicopters will fire their door-mounted machine guns to ''maintain crew skills and ... operational effectiveness''.

East Timorese non-government organisations expressed concern yesterday about the exercises.

Australian Defence Force Academy senior lecturer and former army officer Clinton Fernandes also questioned their military necessity and political wisdom. ''There is plenty of opportunity for this sort training to be conducted in Australia before units are deployed to East Timor,'' Dr Fernandes said.

''It is far from clear what current security contingency in East Timor requires regular training in the use of Black Hawks as helicopter gunships.

''At a time when East Timor needs peace and quiet, this sort of activity sends the wrong signal.''

At a meeting with La'o Hamutuk, a prominent East Timorese non-government organisation, an ISF liaison officer confirmed that a ''visual scan only'' would be employed to check that there were no people or wildlife in the firing area.

Asked how local communities would be informed, the ISF said that East Timorese authorities were responsible for providing warnings.

But inquiries by The Canberra Times confirmed that no special precautions were being taken apart from the newspaper advertisements.

The gunnery trials are taking place over three days and will be repeated monthly.

According to the ISF, the helicopter exercises will help bring ''stability, security and confidence to the Timorese''.