David Barrett, Telegraph, May 14, 2015

More than 700 Britons of “significant concern” have travelled to Syria, the country’s top counter-terrorism officer has disclosed.

Mark Rowley, the Metropolitan Police assistant commissioner, revealed the new figure as he said he was becoming increasingly concerned that young people who would once join street gangs are now turning to terrorism.

More than a third of the 700 suspects who have been to follow jihad in Islamic State are now back in Britain, Mr Rowley confirmed.

The “make up” of terrorism is changing with more girls, women and younger boys becoming involved, he said.

“It is a replication of gang crime,” said Mr Rowley.

“Young people who were getting drawn into gang crime, particularly those with troubled histories, are now turning to this.”

Data released by the Met showed last year saw the largest number if terrorism arrests on record.

There were 338 suspects detained in 2014/15 – the equivalent of almost one a day.

Of those 11 per cent were female and 17 per cent were under 20.

“The make up of terrorism is changing,” said Mr Rowley.

“We would not have seen that five or 10 years ago.”

The 338 arrests last year compared with just 254 in the previous 12 months.

Nearly eight out of 10 of the suspects arrested were British nationals, according to the Scotland Yard figures.

Sir Bernard Hogan-Howe, the Met Commissioner, said he supported the Conservative Government’s announcement that it would seek to update powers to obtain communications data.

Theresa May, the Home Secretary, said last week there would be a renewed push to bring in a so-called “snooper’s charter” to maintain the security services’ ability to monitor electronic communications by terrorists and criminals.

“The Home Secretary’s announcement is a welcome development,” Sir Bernard said.

“It’s a vital one that has been delayed too long.”

Mr Rowley also said he thought the Government’s “Prevent” strategy, which aims to stop people being drawn into extremism and terrorism, may need broadening.

He said there may be a case for introducing new powers to make it compulsory for suspects to become involved with Prevent, which is currently only on a voluntary footing.