Australia on Tuesday raised the terrorism threat level against the police force to high for the first time, saying there were small but growing numbers of citizens involved with jihadist groups and intent on attacks.

Australian Federal Police said the decision had been taken based on intelligence-gathering and discussions with partners and was in line with the broader threat for the country, also raised to high in September.

"Recent events in France, Canada and Australia serve as a sobering reminder of the risks associated with policing," the federal  force said in a statement.

Three police officers were among the 17 people killed in France this month during three days of Islamist attacks, while in Canada two soldiers were killed in separate incidents last October, including one shot while standing guard at the War Memorial in Ottawa.

Australia had its own brush with terrorism when a lone gunman held customers and staff at a Sydney cafe hostage in December, in a stand-off that left two hostages and the gunman dead.

The heightened alert, raised from medium to high, also comes after a "known terror suspect" was shot dead in Melbourne in September after stabbing two police officers, a day after the Islamic State group called for Muslims to kill Australians indiscriminately.

Both policemen survived the attack.

"While relatively small, there are increasing numbers of Australians who are connected with or inspired by overseas terrorist groups such as the Islamic State of Iraq and the Levant, with the intent and capability to conduct an attack against police," the federal police said in a statement.

The factors that had led to the elevated general terrorism threat level for Australia to high in September had persisted and the security environment was "increasingly complex and challenging", it said.

"This is the first time the level has been at high for Australian police," a federal police spokeswoman said.

"This change is not due to any specific threat but means that a terrorist attack against police is assessed as likely."

Australian state and territory police forces said the assessment was a reminder that police, often the first responders to incidents, needed to be vigilant about security.

"We are easy to target... you simply call us and we come," Western Australia's acting police commissioner Stephen Brown said.

"You've seen the way this has played out across the world; that either in response or by being targeted because they're highly visible, police are being acted out against." (AFP)