US troops have started arriving in Iraq to help its army fight off Islamist extremists.

ISIS has taken control of large parts of the country - with more than 1,000 people thought to have been killed in the uprising in the last few weeks.

The Pentagon insists America's involvement isn't an intervention though.

The Pentagon's Rear Admiral John Kirby has been giving more details about the deployment:

Meanwhile, in Britain, fears are growing about the threat from home grown jihadists as the conflict in Iraq risks spreading into Afghanistan once UK troops withdraw.

The former head of Britain's Armed Forces has warned increasing numbers of British Muslims could be radicalised if conflicts like Syria and Iraq are not brought to a halt.

The Government estimates around 400 British-born fighters are currently in Syria and Iraq.

Three men – two from Cardiff and one from Aberdeen – featured in a recent promotional video made for ISIS insurgents released last week.

The threat posed by jihadists returning from such conflicts to Britain may increase, Lord Richards said.

British troops are due to withdraw from Afghanistan at the end of this year and Lord Richards said he feared a similar situation could arise.