Counter-terror chief reveals scale of extremist threat to UK

Police operations to stop terror attacks reach highest level for years as Britons return from Syria

Police resources are being "stretched" as the number of operations to prevent extremist attacks reaches its highest level for years, Britain's most senior counter-terrorism officer has warned.

Assistant commissioner Mark Rowley, head of specialist operations at Scotland Yard, has issued a statement about the scale of the threat posed to the UK by the rise of Islamist extremism in Syria and Iraq.

Officials are removing 1,000 pieces of illegal content from the internet every week, including beheadings and other brutal murders. Four in five of these are related to Iraq and Syria.

"So far this year we have made 218 arrests and are running exceptionally high numbers of counter-terrorism investigations, the likes of which we have not seen for several years," said Rowley.

The assistant commissioner said police had disrupted several terror plots of "varied sophistication, from individuals planning to carry out spontaneous yet deadly attacks to more complex conspiracies, almost all seemingly either directed by or inspired by terrorism overseas".

Although at least 500 jihadists are suspected of travelling abroad, only 16 returning from Syria have been charged under the Terrorism Act and only three convicted, reports The Times. It also emerged yesterday that about 30 British jihadists are believed to have died fighting alongside Islamic State and other militant groups in Syria.

About 50 people a week are being referred to radicalisation programmes, according to The Guardian, and police have recorded 66 missing people whose families fear they might have travelled to Syria.

Rowley told the BBC that "many" Britons are now returning from Syria to the UK and police are arresting and prosecuting "many" of them. But he said that police are being "stretched" by the increase in operations. "The volume, range and pace of counter-terrorism activity has undergone a step-change," he said.

Rowley also noted that the police increasingly hear from communities that what is happening in Syria is "not Islamic at all" and is "nothing like Islam".