Twitter has suspended the account used by Somali militants after the insurgents used the micro-blogging site to post a hostage video and death threat.

Somalia’s al-Qaida-linked militants said today that they will kill a French hostage they have held for more than three years in the wake of a botched rescue operation by the French military.

France is on a heightened state of alert after President Francois Hollande raised terror threat levels.

The French Defence Ministry said the captors of a military agent killed him during a French commando raid in Somalia.