The East Timor peacekeeping force is investigating allegations that Australian soldiers have been sexually harassing local girls.

Reports said up to six sisters from one family were terrorised on at least two nights when the soldiers called at their home in the capital Dili.

Major-General Peter Cosgrove, commander of the multinational Interfet force, said he was furious and had issued a stern warning to all peacekeepers.

He said they had so far not managed to identify the culprits.

''Heaven help them if we catch them,'' General Cosgrove told the Australian newspaper. ''When I heard about it at the time I was very angry and I remain very angry.''

The newspaper said the men were drunk and shirtless when they forced their way into the house on 24 November and 16 December shouting that they ''wanted a lady'' and making sexual suggestions.

The six sisters, who had just been reunited with their parents, told the soldiers they had the wrong place.

One of the girls threatened to call the military police on the second occasion, but she said one soldier still refused to leave, telling her ''I don't care''.

She told how the lights in the house then went out and with the family huddling outside she ran for help, leaving the soldier inside.

Apology

General Cosgrove said he had no reason to doubt the girl's account.

"We've apologised to the young women involved. We were aghast at this, as are 99.9% of our people here," he added. "I dare say the other 0.1% are feeling very guilty and stupid.

"Every day we've got people putting their lives on the line for East Timorese and they do that happily and gladly, but they don't respond well when a very small proportion of the group lets the side down."

"We're angry and we're taking some fairly strong steps to both find any culprits and to make sure that people understand that it's not on."

All Australian-led Interfet troops have now been warned about the importance of maintaining proper conduct.

Interfet troops were sent to East Timor in September after pro-Indonesian militia unleashed a campaign of violence when the territory voted to separate from Indonesia.