Headteachers say they fear pupils will use Easter holidays to flee UK and join Isis in Syria

Three London schoolgirls who evaded security used half term to escape

Left to right: Amira Abase, Kadiza Sultana and Shamima Begum waught on CCTV at Gatwick airport on their way to Turkey last month

Two headteachers have admitted they fear pupils will not return from the Easter holidays because they are planning to join Isis in Syria.

A former chief prosecutor has warned they are not telling police of their concerns because they do not want to see students face criminal charges.

The school leaders confessed to Nazir Afzal that they were “scared” some teenagers will use the break to attempt to join the so-called Islamic State, he told The Times.

One principal told him he has been approached by parents fearing their children would flee almost every day, Mr Afzal said, adding: "Both said they were scared of the Easter break and would be very relieved if all their pupils came back after the holidays."

He told the newspaper the teachers were from different parts of London and knew of more than a dozen boys and girls whose parents believed they had been “groomed and seduced” by Isis’ violent ideology.

Mr Afzal stepped down this week as chief prosecutor for the north west of England after leading high profile cases against former BBC presenter Stuart Hall and weatherman Fred Talbot.

He said parents’ fears that their children will be prosecuted is preventing them from informing authorities about possible radicalisation and teachers would prefer a “preventative”, rather than criminal, approach.

Mr Afzal added: “(The headteachers) didn't know what to do. They’re told to direct parents to the police, but the parents don’t want the police to be told and the heads don’t want to criminalise their pupils…It can't just be a police responsibility because sadly many people in our communities don't trust the police.”

His warning came after three schoolgirls from the Bethnal Green Academy in east London fled to join Isis in Syria, joining another 15-year-old girl who was already there.

They disappeared during the half-term holiday in February, possibly after being radicalised online and instructed by Isis recruiters on how to evade security.

Police had written letters to the girls’ parents after their friend joined the group, asking permission to take formal statements. But they were handed to the students themselves rather than being delivered to their homes and were found unopened in school textbooks after they left.

A High Court judge has subsequently confiscated the passports of four other pupils at the school after concerns were raised by the local council.

David Cameron confirmed yesterday that the three schoolgirls could face criminal charges if they return to the UK.

“Whoever has gone out to join a terrorist organisation is breaking the law and has to face the consequences of breaking the law,” the Prime Minister said.

Hundreds of British men and women are believed to have joined Isis and other terrorist groups in Syria and Iraq over the last two years.

Among them is Mohammed Emwazi, the former London university student believed to be the masked militant known as “Jihadi John” seen in Isis’ gory execution videos.

26-year-old 'Jihadi John' is believed to have left Britain in 2012-13

In 2013, 25 arrests were made for Syria-related offences and last year that number rocketed to 165.

A group of young British Muslims has declared their own ideological “jihad” against Isis and all other terrorist groups and numerous organisations are working to counter its online propaganda.

“We ask Muslims from all walks of life, regardless of the school of thought to which they belong, to stand united against extremists who have hijacked the true teachings of Islam,” the Muslim Youth League UK said.

“We call upon scholars and community leaders to raise a united and unwavering voice against extremism.”

Additional reporting by PA