Ananova:

A photograph taken from a surveillance tape shows two suspected terrorists heading toward their gate at an airport the same day of the terrorist attacks.

The image shows the pair before boarding a commuter flight from Portland International Jetport to Boston the morning of September 11.

Investigators say once in Boston, the men switched to American Airlines Flight 11, which was hijacked and crashed into one of the World Trade Centre's twin towers in New York.

One of the men, believed to be Mohamed Atta, has a bag over his shoulder.

The other, said to be Abdulaziz Alomari, is seen reaching down as if to take something from the conveyor belt at a security checkpoint.