It was developed in the 1990s for use in what the US describes as "moderate-risk environments" - where enemy air defences remain a threat, or in areas which may have been contaminated by chemical or biological weapons.

With its bulbous nose, the aircraft has a wingspan of almost 49 feet (15 metres) and weighs 2,250 lbs (1,020 kg) when kitted out for reconnaissance, surveillance or target finding.

It is flown from the ground station van by a "pilot" with a joystick and monitoring screens, including one giving the view from a colour TV camera in the aircraft's nose. Each craft also has an infra-red camera for poor light or night missions, and radar to scan through smoke, clouds or haze.

They fly at no more than 140mph but can stay airborne for nearly 24 hours at a time, cruising at up to 25,000 ft (7,500 m).

Their slow speed makes them vulnerable to anti-aircraft fire, however. Iraq says it has this year shot down two Predators over its airspace where the aircraft have seen extensive use.

In addition to its deployment over southern Iraq and Afghanistan, Predators were used also Bosnia and Kosovo.

More recently one was used by the CIA to kill six al-Qaeda suspects in Yemen in November 2002.