[DailyMail] o 250 British based 'extremist tourists' have returned home from fighting
o Figure includes several 'veterans' who fought in Afghanistan and Pakistain
o Security forces thwarted 'serious plot' by jihadis returning last Autumn
The returnees were said to be planning a Mumbai-style gun attack on civilians in a crowded place, possibly London. They are now being monitored by the security services, The Sunday Times reports.
A senior Whitehall security official told paper: 'Well over half of those who travelled out have come back.'
Last week it was announced that krazed killer videos which help to radicalise impressionable young men are to be blocked from the internet in the UK.
The Home Office is in talks with web companies to refuse access to violent films hosted overseas 'at a network level', MailOnline can reveal.
The plans for what will effectively be 'cyber border controls' have been drawn up by James Brokenshire, promoted to immigration minister at the weekend.
Around 2,000 Europeans are thought to be fighting in Syria, including at least 200 known to the British security services.
Since February 2010, the Counter Terrorism Internet Referral Unit (CTIRU) has taken down more than 21,000 pieces of illegal terrorist online content.
If the CTIRU and prosecutors deem material to be illegal it can be blocked from parts of the public sector, including schools and hospitals but this does not extend to domestic users and filters can be turned off.