Islamic State supporters
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What threat does IS pose to UK?

David Cameron has announced what he called a "full-spectrum response" to the attack on British citizens at a resort in Tunisia on Friday.

The prime minister said that so-called Islamic State posed an "existential threat" to the UK and called for a united response with other nations which share the same values.

The BBC's Frank Gardner has been looking at the security challenges which lie ahead, both at home and overseas.

  • 29 Jun 2015
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