The head of ASIO is standing by comments that refugees are not to blame for terrorism.

ASIO director-general Duncan Lewis seriously disturbed the One Nation party, whose Senator Malcolm Roberts tweeted; 
“If ASIO can't see a link between refugees and terrorism we are in far greater danger than I thought”.

Mr Lewis says tens of thousands of refugees have come to Australia in the last decade, but “very few of them have become subjects of interest for ASIO and have been involved in terrorist planning”.

Mr Lewis conceded that three fatal attacks in Australia in recent years have involved refugees or the children of refugees.

“I am not denying that … but context is very important,” he said.

“The reason they are terrorists is not because they are refugees but because of the violent extremist interpretation of Sunni Islam that they have adopted,” the ASIO head told the ABC.

Mr Lewis said they were radicalised by viewing online material, which could have been accessed by anyone, in virtually any part of the world.

“I am not here to vilify the Islamic community. I am here to keep the Australian community safe and ASIO works very hard every day on that particular issue,” he said.

The issue was given new weight by comments from former prime minister Tony Abbott this week, who warned that that public officials should not “deny facts” about terrorism in Australia.

Senior LNP figure Peter Dutton backed the ASIO boss.

“The point Mr Lewis was making that others have made, and I’ve made on a number of occasions, is that we do have problems where people are indoctrinated online, where they have an impressionable young mind,” he said.

“Our problem is with people of any background, whether they are born here or when they come here, who are radicalised and go out and commit these offences.”