MONTREAL (AFP) - With a combination of new anti-terror measures and appeals to parents, Canada is striving to keep its youths from joining Islamist extremist groups and leaving to fight in Syria.

Last weekend, the drive seemed to pay off.

Ten would-be militants were arrested at a Montreal airport as they waited to board a flight to Turkey, a popular crossing point into neighbouring Syria.

There, the young men had hoped to join the Islamic State in Iraq and Syria (ISIS) group, according to an anti-terrorism task force.

The youngest were 15 years old, and their friends were no older than 18.

Their passports were seized but the youths were released after being questioned, said the Royal Canadian Mounted Police-led Integrated National Security Enforcement Team.

Investigators remained tight-lipped Wednesday about the arrests, saying only that a tip from a concerned parent helped authorities prevent the youths from leaving Canada.

The police probe is continuing and "the families and friends of the young persons have been met by investigators," the RCMP said in a statement, urging all parents to monitor their children's online activities.

Quebec province's public safety minister, Lise Theriault, appeared baffled by the phenomenon.

"It's hard to conceive that a young man who grew up in Canada, who attends school, who is well-integrated, would want to wage war," she told a press conference.

"What concerns me most is that these are (Canadian-born) children of immigrants," she said.

FAMILIES 'AT A COMPLETE LOSS'

The RCMP noted: "These are very difficult times for the relatives and loved ones of the persons arrested, as the decision to leave the country was not that of the family, but of a single family member.

"As a result, family members often find themselves at a complete loss and unable to understand the decision made by the youth."

Authorities have new tools at their disposal to stem the tide of militant travellers after Parliament voted in early May to update Canada's anti-terror laws.

The new legislation dramatically expanded the powers and reach of the Canadian Security Intelligence Service, allowing it to actively thwart terror plots and operate overseas for the first time.

It also criminalises the promotion of terrorism and makes it easier for police to arrest and detain individuals without charge.

The controversial measures were enacted in response to the first attacks on Canadian soil last October, when a gunman killed a ceremonial guard and stormed parliament, and a soldier was run over in rural Quebec.

Canadian Public Safety Minister Steven Blaney, commenting on the latest arrests, touted the new national security framework as needed "to better protect Canadians against the ever-evolving jihadi terrorist threats".

"The international jihadist movement has declared war on Canada," he said, justifying Canada's campaign of air strikes against the ISIS group.

In the meantime, militants' departures from Canada have ramped up, with at least a dozen men and women in their teens or twenties having attempted to reach Syria since January, including a woman who had taken an online religious course only to be recruited by the teacher to become an ISIS fighter's bride.

Several of the would-be extremists also attended the same high school in a Montreal suburb where a controversial imam, who years ago successfully challenged his detention without trial over suspicions that he was an Al-Qaeda sleeper, taught religious studies.

According to the RCMP, more than 100 Canadians have joined the ranks of the Islamic State group in Syria and Iraq.

Some are now dead, such as a former Ottawa university student who converted to Islam and was reportedly killed in December near Kobane in Syria, and four cousins from Calgary whose deaths devastated their families, which had fled conflict in Somalia to start new lives in Canada.

Others post about their purported Middle East adventures on social media networks or in Twitter messages.

A lawyer for one the youths prevented from leaving Canada over the weekend told public broadcaster Radio-Canada that his client had been a "victim" of ISIS online recruiters who promised "a better life" to angst-ridden teenagers in search of guidance.