Islamic State group Militants in Syria. (Photo: Reuters)
Britain debated Sunday how to stop teenage girls joining the Islamic State group in Syria after three high-achieving youngsters became the latest to run away from home.
Close schoolfriends Kadiza Sultana, 17, and 15-year-olds Shamima Begum and Amira Abase left their east London homes on Tuesday and flew to Istanbul, raising concerns they would travel on to Syria to join IS jihadists.
All three were spoken to in December by police investigating the disappearance of a friend who went to Syria but Scotland Yard insists there was "nothing to suggest at the time that the girls themselves were at risk".
Others question whether warning signs were missed and more should have been done to stop them travelling.
Someone using a Twitter account in Begum's name last Sunday seems to have contacted Aqsa Mahmood, a woman from Glasgow, Scotland who reportedly travelled to Syria last year to marry an IS group fighter.
Mahmood's family, who strongly condemn her actions, have questioned why more was not done to take action in the wake of this.
"We are aware from contacts with the Special Branch of police that her social media contact is regularly checked and regularly monitored," Aamer Anwar, lawyer for the Mahmood family, told the BBC Sunday.
"The fact that she is now engaging with other young people and trying to recruit them, they're saying 'what exactly is the security services doing in this country?'"
The debate reflects an issue of growing concern in Britain.
Counter-terrorism experts estimate that around 50 women have travelled from the UK to Syria to join the IS group, while tales of "jihadi brides" have become a staple of Britain's tabloid press.
Some 550 women from across Europe have travelled to Iraq and Syria, where they often marry fighters and help to recruit others, according to a study from the Institute of Strategic Dialogue think-tank last month.
Opinions vary on what can be done to stop it.
Under a new law which came in this month, the passports of Britons suspected of travelling to Syria or Iraq can be seized before travel -- although the girls in this case were not suspected in advance.
Prime Minister David Cameron's government also plans to introduce additional measures in the coming months including exit checks on passports and enhanced screening at airports.
Turkish Airlines, with whom the girls flew to Istanbul, said its responsibility was checking passengers' visas and pre-flight security issues were the "responsibility of official airport authorities."
Cameron said Saturday that the case highlighted that "the fight against Islamist extremist terror is not just one that we can wage by the police and border control".
Calling the situation "deeply concerning", he urged schools, universities and colleges to recognise their roles.
But Sayeeda Warsi, Britain's first female Muslim Cabinet minister who resigned last year over the government's Gaza policy, warned there was no "single journey to somebody becoming a terrorist".
She highlighted the role of the Internet in radicalising young Muslims in an interview with Sky News Sunday.
That was echoed by Ross Frenett of the Institute of Strategic Dialogue, who stressed more effort should be made to counter online propaganda.
He also advocated more help for families like those of the three girls -- who Saturday issued emotional appeals for their return -- in identifying the signs of radicalisation.
"An awful lot of extremism... is people looking for a sense of belonging," Frenett said.
"That's not unique to people who are maladjusted. An awful lot of extremism of all types actually comes from people with well-off backgrounds who tend to be very well adjusted".