Media playback is unsupported on your device Media caption The home secretary says the threat to the UK is serious, as Alan Soady reports

New powers to tackle extremist groups are being looked at by the government, the home secretary has said.

Writing in the Daily Telegraph, Theresa May said what have been dubbed "Asbos for terrorists" could be introduced for those who try to radicalise others.

Groups believed to be inciting terrorism could also be banned under new orders, even if they "fall short of the legal threshold", she said.

In response, Labour said more detail was needed on the specific powers.

Home Office minister James Brokenshire said there would be no "knee-jerk reaction" following the killing of US journalist James Foley by Islamic State (IS) militants.

Authorities are seeking to identify a man with an English accent who appeared in footage of the killing.

Mr Brokenshire said the government would focus on ensuring existing legislation was as effective as possible, and would consider "measures attached to individuals" engaged in extremist activity - as well as organisations.

'Deadly threat'

In her article, Mrs May described the "very deadly threat" to the UK from terrorism at home and abroad, saying she wanted to build on the work of the Extremism Task Force set up after the murder of Fusilier Lee Rigby in London last year.

Media playback is unsupported on your device Media caption Zubeda Limbada, from Connect Justice, on dealing with radicalisation

The UK would also "make Prevent a statutory duty for public bodies", she said.

The Prevent programme - part of the government's counter-terrorism strategy - aims to tackle radicalisation by working with a range of sectors, including faith, education and the justice system.

"I am looking again at the case for new banning orders for extremist groups that fall short of the legal threshold for terrorist proscription, as well as for new civil powers to target extremists who seek to radicalise others," she added.

The Extremism Task Force report had suggested that new civil measures - akin to powers to tackle anti-social behaviour - could be introduced to target the "behaviours extremists use to radicalise others". At the time, they were widely reported as terror Anti-social Behaviour Orders (Asbos).

Some of the Islamic State recruits are active on social media, and keen to recruit others Countering the call to jihad

Mrs May said that since 2010, more than 150 foreign individuals had been excluded from entering the UK, including "hate preachers".

She added the UK had improved its ability to address the problem of extremism online - with 28,000 pieces of terrorist material removed from the internet so far this year.

Mrs May added that "people who insist on travelling to fight in Syria and Iraq will be investigated by the police and security services".

The home secretary outlined some of the measures which are in place to tackle those that travel abroad to commit acts of terror:

The rules on the Royal Prerogative, which allows the removal of passports of British citizens who want to travel abroad to engage in terrorism, had been toughened. So far, 23 people planning to travel to Syria have had their passports withdrawn

Those with dual nationality who want to fight in Syria or Iraq can be stripped of their citizenship and excluded from the UK

The recent Immigration Act means naturalised Britons who are fighting overseas can be stripped of UK citizenship

If approved, the Serious Crime Bill would make it illegal to travel overseas to prepare and train for terrorism

But shadow home secretary Yvette Cooper said more should be done to respond to the "serious problem" of people travelling abroad to fight.

"I remain concerned that the government is not addressing the gaps in the Prevent programme - especially the lack of support for community-led approaches to preventing radicalisation.

"And the home secretary also needs to respond to the concerns raised by the current and previous independent reviewer of terrorism legislation about the decision to weaken control orders, where they have advised that stronger measures should be put in place."

Media playback is unsupported on your device Media caption Ex MI6 counter-terrorism boss Richard Barrett says the government needs to be seen to be taking action

Currently, TPims are used to restrict movement, the use of computers and mobile phones and meetings with others. They replaced the previous system of control orders - which were more restrictive - in 2011.

Committing a crime

The BBC's political correspondent Ben Wright said the government was not planning a new raft of legislation and there would not be time before the election to introduce new laws even if it wanted to.

John Gearson, a professor of security studies at King's College, London said banning borderline groups could help deter recruitment.

"Undermining their ability to propagandise and to actually identify people is a good thing," he said.

"But the problem is if these people are looking for an ideology, something to fill their lives, they are going to find it whether or not we ban an organisation."

The Muslim Council of Britain has urged Muslims to play their part in countering radicalisation and report any wrongdoing to the police.