The U.S. has warned of possible attacks against Western targets in retaliation for its military campaign in Syria and Iraq.

It's asked Turkey for more help in fighting Islamic State militants - as the extremist group gain more control of the town of Kobani on the Syria / Turkey border.

Elsewhere, it's emerged that some people, calling themselves Islamic State, have issued death threats to staff at Twitter.

The social media company shut down the accounts of militants who tried to use twitter to recruit others, where they boasted and even posted pictures in an attempt to support their hate campaign.

The company's chief executive Dick Costolo told a Vanity Fair event that people associated with the group used twitter to say employees and management should be assassinated.