Hundreds of British Muslims have travelled to Iraq to fight for the extreme jihadist group ISIS, terror experts have said. The Government believes more than 500 British citizens have left the UK and gone to join rebel fighters in Syria, with many of them feared to have crossed the border to join the uprising in Iraq. The ruthless ISIS (Islamic State in Iraq and Syria) extremists control large areas of land in Syria and are now turning their attention to Iraq and particularly Baghdad, having already taken the cities of Mosul and Tikrit. Meanwhile, British security experts are also looking at the possibility that home-grown extremists trained by the ultra-violent group may bring terror back to the UK.
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British Muslims are heading to Syria to fight with extremist rebel group, ISIS
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Now hundreds of them are feared to be crossing the border to fight in Iraq
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Security services looking at suggestion Brits fighting with insurgents there
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Ultra-violent ISIS has already taken Mosul, Iraq's second city, and Tikrit
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Pictures emerge today of more bloodshed as they head towards Baghdad
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Meanwhile, experts fear ISIS-trained Brits may bring terror tactics home
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PM David Cameron has spoken to head of Nato about situation in Iraq
'As the Prime Minister has said, the greatest extremist activity and jihadist threats to the international community are in @placeholder.