Officers from ACT Policing and the Australian Federal Police were told to take extra precautions this week after police accountant Curtis Cheng was gunned down in the western Sydney suburb of Parramatta.

More than 200 NSW police officers swooped and five males were arrested during a series of counter-terrorism raids across Sydney's west and north on Wednesday that police said were linked to the shooting.

It is understood ACT Policing's sworn officers have been advised to be more vigilant than usual and to wear their guns at all times this week.

A similar directive was issued to officers at the Parramatta policing hub, where employees are watching closely to see what security measures will be tightened on the back of the attack.

Federal police had already raised the terrorism threat level against officers to high in January, months after terror suspect Numan Haider was shot when he attacked an AFP officer in Victoria last year.

Australian Federal Police Association chief executive Dennis Gellatly hadn't been formally updated on the changes but said firearms were a standard issue item and part of a police officer's use of force options.

"AFP members have been under a heightened level of security for some time now and, tragically, the Sydney shooting is a stark reminder for police and the community that the threats are real and the need to remain vigilant is important.

"It is appropriate that our police are reminded by their senior officers of the need to be armed when in public, for their own safety and for the protection of the community."

A spokeswoman for the AFP, which takes in ACT Policing, said it was not appropriate to discuss any specifics relating to the security of its staff or infrastructure.

She would not be drawn on whether security had been tightened at federal police headquarters in Barton or at ACT Policing buildings around the territory.

"On a day to day basis, the public should not expect to see any major difference," she said.

"Recent events are a timely reminder for police to ensure that current security measures are appropriate to the current threat level."

The spokeswoman said while there was no specific threat to members, the agency would continue to assess and review its security procedures and measures.

"The safety and security of the community and our officers and staff is of the utmost priority."

The federal police spokeswoman encouraged members of the public to be aware of current events but to go about their lives as normal.

AFP Commissioner Andrew Colvin acknowledged in June that police faced greater challenges under the heightened threat alert.

He said at the time he was "greatly concerned" about Australian children being preyed upon by terrorists and lured overseas as foreign fighters.