Two national Muslim organizations say they are troubled that Prime Minister Stephen Harper last week drew a link between radicalization and mosques.

Harper made the remark last Friday when he was answering a question about the Canadian government's new anti-terrorism legislation. The measures unveiled in Bill C-51 include criminalizing advocacy for or promotion of a terrorist act. Another measure lowers the threshold needed for police to arrest somebody they suspect may commit a terrorist act.

Asked how to distinguish between teens messing around in their basements and someone who is radicalized, Harper said it would be a serious offence "no matter who you are."

"It doesn't matter what the age of the person is, or whether they're in a basement, or whether they're in a mosque or somewhere else," Harper said Friday in Richmond Hill, Ont.

Harper takes questions on anti-terror bill15:48

The National Council of Canadian Muslims (NCCM) and the Canadian Muslim Lawyers' Association (CMLA) said in a press release Monday that they are "deeply troubled" Harper "implicated Canadian mosques as venues where terrorism is advocated or promoted." In a press release, the groups demanded Harper apologize.

Amira Elghawaby, human rights co-ordinator for the NCCM, said the organization found Harper's comments "extremely divisive."

"Considering that we've seen anti-Muslim violence and vandalism at places of worship, it was very disturbing to see the prime minister create this kind of impression in the minds of Canadians, that there's something wrong going on when there isn't anything of that sort," Elghawaby said.

High standard of responsibility

Elghawaby said imams and mosque communities have called authorities when they have concerns about someone.

"Whether it was a slip of a tongue — which I highly doubt — but whether it was or not, I think our leaders have to be held to a very high standard of responsibility in terms of setting a tone where all Canadians feel welcome in this country and where all Canadians know that they're together on any issue that's challenging them," she said.

NDP Leader Tom Mulcair said the two groups are right to demand an apology.

"It was irresponsible of the prime minister to throw the mosques into his comments. It was a form of Islamophobia and it was wrong. So he should realize that he was wrong to do that and simply apologize to the Muslim community," Mulcair said Monday after question period.

Mulcair: Harper mosque comment form of 'Islamophobia'0:50

A spokesman for Harper said in an email to CBC News that the prime minister did not say all radicalization occurs in mosques.

"Radicalization towards jihadi terrorism can happen anywhere," Carl Vallée wrote.

"Following the attacks last fall, the prime minister specifically thanked members of the Muslim community for categorically and unequivocally condemning the attacks, and recognized the Muslim community for their efforts in fighting radicalization," he added, referring to a Dec. 4 speech to a Muslim association in Toronto.

'So wrong' to create wedge issue, MP says

Harper and other officials have repeatedly cited jihadi terrorism in speeches and comments about the changes proposed in Bill C-51.

Liberal public safety critic Wayne Easter said many Canadian mosques are doing all they can to prevent radicalization. Easter says Harper should be more cautious in what he says.

"One of the concerns I have in watching Prime Minister Harper's stage-managed production in Toronto, when it should have been done right here in the House of Commons, is that he seems to be suggesting, 'Be afraid, be very afraid,' and turning this into a political issue," he said.

Easter said Harper is trying to use security as a wedge issue for political purposes.

"That is so wrong for the leadership of a country to do," he said.

Meanwhile, an Ottawa imam told a Senate committee Monday that Canadians must work harder to prevent young people from becoming radicalized in the first place.

Zijad Delic told the Senate national security committee Monday that there is not enough talk about steering vulnerable people away from extremism. Instead, the focus is on trying to deradicalize them after the fact.

Political leaders, social services, teachers and others need to "find ways of tackling" the lure of extremism, Delic said.

with files from The Canadian Press