Extremist recruiters have been likened to paedophiles after online grooming was blamed for luring Britain's youngest suicide bomber into the clutches of Islamic State (IS).
Talha Asmal, 17, reportedly detonated a vehicle fitted with explosives while fighting for the group in Iraq.
Meanwhile, separate reports emerged that British Muslim convert Thomas Evans is believed to have died fighting in Kenya fighting for extremist group Al Shabaab.
Talha's family said that despite him never exhibiting any extreme or radical views, he had been exploited by extremists on the internet "in a process of deliberate and calculated grooming of him".
Qari Asim, an imam at the Makkah Mosque in Leeds, said recruitment was mainly taking place online.
"The perpetrators are pretty much acting like paedophiles, they groom these young individuals over time - radicalisation isn't an overnight process," he told the BBC.
"They prey on these vulnerable young people and brainwash them, and religion is a unique passion so they tend to use religion to brainwash these young individuals for their own political aims and gains."
Police and politicians have repeatedly raised warnings about the issue of online grooming.
Sir Bernard Hogan-Howe, the country's most senior police officer, spoke today of the varied nature of the threat faced by the UK.
Speaking ahead of a police counter-terrorism conference, the Metropolitan Police Commissioner said: "Today's terrorist may of course be a hardened member of an organised terrorist 'cell', but may very well also be a lone disaffected youth radicalised by extremist material on his home computer.
"Some of those travelling to Syria are fulfilling a long-standing Jihadi ambition. But others who travel to Syria are youngsters fooled by propaganda - out of their depth and running out of time.
"The police must find a way to deal with both."
Talha's death has not yet been officially confirmed, but his parents said photographs showing a youth purportedly named Abu Yusuf Al Britany appeared to depict their son.
He is alleged to have fled his home in Dewsbury, West Yorkshire, in March, to join IS - also known as Isis or Isil. The town was previously embroiled in Islamist extremism when it emerged as the home of Mohammed Sidique Khan, the ringleader of the July 7 attacks in London.
Unbeknown to them and completely against their will, Talha's family said he travelled to Iraq via Turkey and fell under the spell of Isis handlers who are "too cowardly to do their own dirty work".
Describing themselves as "a close-knit, hard-working, peace-loving and law-abiding British Muslim family", they said they unreservedly condemned and abhorred all acts of violence.
"As a family we would like to take this opportunity to unequivocally state that Isis are not Islam," they said.
"They do not represent in any way, shape or form Islam and Muslims and we are no longer prepared to allow a barbaric group like Isis to hijack our faith.
"Isis - not and never in our name."
Shahid Malik, a former government minister and a family friend of the Asmals, described them as "a beautiful, caring, peace-loving and incredibly humble family".
The former MP for Dewsbury said: "It is disturbing to see how relaxed he looks in the Isis photographs allegedly taken just prior to his suicide mission.
"He looks at peace. It's like he's ready to go and meet his maker. This is a clear indication of just how successful the evil Isis groomers have been in poisoning and brainwashing Talha and kids like him.
"We must defeat Isis in mosques and communities across the country. This is a generational struggle and everyone must be willing to rise to the challenge."
Former radical Muslim recruiter Abu Muntasir, considered the "godfather" of the British jihadi movement, said he refused to accept that youngsters going to fight in the Middle East have no choice.
He told ITV's Good Morning Britain: "There is grooming, no doubt - I know how we used to convince people by ignoring a lot of facts on the ground, ignoring reality and alternative views amongst Muslims and Muslim teaching.
"So the parents need to have more communication with their children, they need to have more of an overseeing aspect of how to be a good parent.
"It's totally despicable what he (Talha) has done, it is an abhorrent crime, and we should be very careful."