Ian Bruce Defence Correspondent US forces in Iraq are using an aircraft older than most of the pilots flying it as the latest "secret weapon" against lethal roadside booby-traps.

Four squadrons of EA-6B Prowler electronic jamming jets - which first saw action over Vietnam in the 1970s - have been deployed to counter the remote-controlled bombs which inflict 80% of fatal casualties on patrolling American troops.

The Prowlers are unarmed, but carry an array of countermeasures which can block the triggering signals used by insurgents to detonate improvised explosive devices(IEDs).

Their electronic pods are fitted with jammers which can blot out everything from military radar to mobile phones and the garage-door openers favoured by Iraqi guerrilla fighters to set off bombs from a safe distance.

Captain David Woods, one of the US Navy's most experienced Prowler pilots, said: "There's no way we can ever know how many explosions we prevent, but I assure you it's effective on the remotely-triggered devices."