Militants from Isis - which is now calling itself Islamic State - called on all Muslims to pledge allegiance to their leader Abu Bakr al-Baghdadi in a statement posted on jihadi websites.
They said: "It is incumbent upon all Muslims to pledge allegiance to (him) and support him...The legality of all emirates, groups, states, and organizations, becomes null by the expansion of the khalifah's (Caliph's) authority and arrival of its troops to their areas."
The Foreign Secretary has been clear on the threat of Isis, but he has ruled out the prospect of any UK military involvement in the crisis.
Iraq’s foreign minister, Hoshyar Zebari, is a natural diplomat. Polite, immaculately dressed, and blessed with a great memory.
Isis has paraded military equipment in Mosul it captured from when the Iraqi army fled in what some see as a "nightmare scenario."