Isil is regrouping in southern Libya with the support of al-Qaeda and preparing for further attacks, according to the Libyan defence minister, who claimed the effort was being spearheaded by Mokhtar Belmokhtar, one of the world's most wanted men.

The unholy alliance of the world’s two most dangerous terrorist groups in Libya is at odds with the public animosity between al-Qaeda and Islamic State of Iraq and the Levant (Isil) leadership.

Ayman Al Zawahiri, the head of al-Qaeda, recently launched a blistering public attack on Isil’s brutal methods and propaganda, branding them “liars”.

But in Libya fighters from the two groups are "actively co-operating", according to Mahdi Barghathi, the defence minister in the UN-backed government in Tripoli.