Cairo - Under increasing pressure from the military, Egypt's deadliest jihadist group pledged allegiance to the Islamic State organisation in a bid to boost recruitment and bolster its fight against the army, analysts say.
Ansar Beit al-Maqdis (Partisans of Jerusalem) has waged an insurgency from its Sinai Peninsula stronghold that has killed scores of Egyptian police and soldiers since the army ousted Islamist president Mohamed Morsi last year.
In response, the army has launched a huge operation in Sinai targeting jihadists and last month began building a buffer zone on the border with Gaza to stem the flow of militants and weapons from the strip.