Blood tests in hunt for Bin Laden

Forensic science specialists have been scooping blood and human remains off the walls of caves in southern Afghanistan hoping to find the remains of al Qaeda leader Osama bin Laden, it was revealed today.

A four-day operation involving 400 Canadian and American troops saw special forces blast open the entrance to a deep cave in the Tora Bora complex which was attacked by coalition bombs in December.

With no indication of Bin Laden's whereabouts since that operation, allied commanders want to know whether he was killed in the two weeks of air strikes on the cave complexes.

US "bunker-busting" bombs smashed through rock and earth to detonate deep inside the caves, and some caves had to be blasted open, having been sealed by last December's attacks.

While defence officials brief privately that they are looking for Bin Laden, officially the coalition is refusing to say that he, or Taliban leader Mullah Omar, are the focus of the search.

Intelligence experts say there is nothing in recently-released video tapes of Bin Laden to date them after December.