Police have been told to be "lenient" with Aborigines and "not to move in unless it is an extreme case of provocation", police sources said yesterday.

In the case of arrests police have been told to take extra precautions while Aborigines are in custody - more frequent cell checks and to issue blankets and bedding only when a prisoner is ready to sleep.

The source said the directive was an attempt to avoid any adverse publicity in the way police handle Aboriginal protests planned for this week and to ensure the safety of Aborigines in custody.

Police sources said a directive was delivered from the Police Commissioner's office early last week that police were to show "patience" when dealing with Aborigines and to "pay particular attention" if any are arrested

"We have been told to be tolerant and lenient and not to move in unless it is an extreme case of provocation," one officer said.

"Basically it's a hands- off policy.

"If they are arrested then we are to take blankets and bedding away until they are ready to sleep."

A similar directive has been issued to the State Rail Authority's Transport Investigation Branch, according to patrol officers.

A spokeswoman for the SRA denied any directive has been issued.

However, one patrol officer said an SRA memo was issued to the branch last Thursday directing them to be more "lenient" towards Aborigines.

The memo shocked patrol officers.

"We are here to uphold the law and if anyone, black, white or brindle breaks the law then we will arrest them," one officer said.

"If someone is vandalism seats or threatening people on a railway platform or generally misbehaving then it is our duty to charge them."

Unofficially, police are expecting trouble from Aboriginal protesters on Tuesday.

A "heavy police contingent", which includes the Tactical Response Group and Special Branch, has been assigned to Mrs Macquarie's Chair - the site of the unofficial Aboriginal Embassy.

TRG members will also be stationed on top of the Harbour Bridge.

* Reports that the SRA Investigative Branch intends to strike on Tuesday because they are being transfer to the jurisdiction of the Police Commissioner from February 1 are incorrect.

One officer said the branch would not dream of disrupting Australia Day celebrations.