A prominent Muslim community leader says the Federal Government's efforts to combat extremism and radicalisation in Australia are a "quantum leap" from its previous approach.

Dr Jamal Rifi made the comments just days after 17-year police force veteran Curtis Cheng was shot at close range and killed outside the NSW Police Headquarters in Parramatta in Sydney's west.

Police have said the 15-year-old gunman, Farhad Jabar Khalil Mohammad, was politically motivated and had links to terrorism.

Dr Rifi, an Australian-Lebanese Muslim GP, told ABC's Radio National program that he felt hopeful after participating in a teleconference call with Prime Minister Malcolm Turnbull and NSW Premier Mike Baird at the weekend.

"The timing of the teleconference, the length of it, the discussion of it with the PM, the Premier and the rest - they've listened to us," Dr Rifi said.

He said the government's approach and tone had greatly improved since Malcolm Turnbull took over leadership of the Liberal Party from Tony Abbott.

"The previous government [led by Tony Abbott] unfortunately put all of the resources into the hard basket end ... there was nothing for early intervention and there was nothing that empowers the mums and dads to be secure and be confident to put their hands up if they notice any change in behaviour in their kids.

"The message from the PM [Mr Turnbull] was very clear - that first of all what we have in Australia is unique and we need to protect it, the fact that extremism is trying to put a wedge and divide us, and we're not going to let that happen."

Sorry, this video has expired GRAPHIC CONTENT: Video shows shooter outside Parramatta police headquarters

He also praised Mr Baird and Minister for Multiculturalism John Ajaka for earning the trust of the Muslim community.

"(They've) tapped into that trust and in a very short period of time."

Dr Rifi called on Muslim men to open channels of dialogue with their children.

He said early intervention would be pivotal to preventing radicalisation and seeking help through community channels did not mean sons and daughters would get into trouble.

"This hateful ideology of the Islamic State is killing more Australian Muslims than non-Muslim Australians," he said.

"Parents should be alert and right now, our Muslim community parents are very much concerned about the fact that we have been targeted by this hateful ideology, so it is in our interest to work collaboratively."

Government and Muslim community united to fight radicalisation

Government frontbencher Steven Ciobo said the fact Farhad was so young added to the tragic nature of the attack.

"It just really reinforces the message that we've been saying for some time that when it comes to these so-called lone wolf attacks, we've got to be vigilant," he told ABC News Breakfast.

"There are radicalised people out there in the community who are looking to inflict harm, looking to murder people.

Police said the 15-year-old gunman, Farhad Khalil Mohammad Jabar, was politically motivated and had links to terrorism. ( Instagram )

"In many instances, Australia's Muslim community will be on the front line when it comes to helping to protect the Australian community because they will often be in a position to have knowledge in relation to people that may become radicalised."

At the weekend the Federal Government reached out to the Muslim community, saying it wanted to work closely with leaders and families at a "grassroots level".

Muslim community leaders said they were shocked by the shooting of Mr Cheng and called for more to be done to stop extremist leaders from recruiting vulnerable youths.

Mr Turnbull also used the opportunity to highlight the need for community engagement following the attack, and urged Australians not to blame or vilify the Muslim community.

"It is also important to remember that the Australian Muslim community will be especially appalled and shocked by this," Mr Turnbull said.

"We must not vilify or blame the entire Muslim community with the actions of what is, in truth, a very, very small percentage of violent extremist individuals."

Parramatta community shaken by fatal shootings

Members of the public have been leaving flowers and messages of sympathy outside the Parramatta police building.

"We sympathise with the kids and the wife [of Mr Cheng]; it could be anybody who's walking past Charles St," said Gary Teh, who came to the site this morning to pray.

"I do come to Parramatta quite often and it's close at heart.

"Our family's quite emotional about it."

Another local who visited the site, Marilyn Warnes, said not enough was being done to stop children from being radicalised by extremists.

"I feel the authorities are not doing anything, or enough, to guarantee our safety, and more of it's going to go on, and I just feel totally exposed," she said.

"It could have been any one of us – it could have been me, it could have been my husband, it could have been anybody.

"This is not the Australia that I grew up in."