US outlaws Zarqawi group

Zarqawi's group has claimed a string of attacks in Iraq

The US has formally listed the insurgent group in Iraq led by Abu Musab al-Zarqawi as a "foreign terrorist organisation".

US Secretary of State Colin Powell said the Tawhid and Jihad group posed a "significant risk" to the national security of the United States.

Mr Powell imposed financial sanctions on the group and froze all its assets.

The group has claimed responsibility for numerous attacks and kidnappings across Iraq.

In the most recent, it said it was behind the dual suicide bombing of Baghdad's Green Zone on Thursday, the first time the high-security area had been attacked from within.

The group is also thought to have been behind the recent murders of British hostage Kenneth Bigley and his American colleagues Eugene Armstrong and Jack Hensley.

Correspondents say Zarqawi is the most wanted man in Iraq. The US has offered a $25m reward for his killing or capture.

On Thursday Britain announced it would freeze any assets held by the group in the UK.