US intelligence agencies say minor al Qaida members are building relationships with members of Hezbollah, sparking fears that the world’s two most sophisticated Islamic terror networks will start co-operating.

The White House has confirmed that troops have captured one of the key members of al-Qaida.

The capture of Abu Zubaydah, al-Qaida’s most senior commander, is one of the most significant developments in the war on terrorism, experts said.