George Robertson: "It must be absolutely right to destroy these terrible weapons"

Defence Secretary George Robertson told a news conference at the Ministry of Defence in London it was thought Saddam Hussein was planning to deploy these "drones of death" in southern Iraq.

He said the Iraqi leader had ordered work to begin in 1995 on the unmanned planes, codenamed L29s.

Mr Robertson said: "They have two under-wing weapon stores containing 300 litres of anthrax.

"If sprayed over a built-up area like Kuwait City it could kill millions of people."

He said: "We suspect he wanted to deploy these drones of death to southern Iraq, where they would have been a threat to his neighbours, and we hit these on Thursday night."

'Terrible weapons'

Addressing those who had questioned the air strikes policy, Mr Robertson said: "It must be absolutely right to destroy these terrible weapons."

The chief of the defence staff, General Sir Charles Guthrie, said the L29 project used specially adapted Czech-made trainer planes, similar to the British Hawk aircraft.

They are fitted with special aerosols under the wings which are capable of spraying anthrax which could travel up to five miles downwind of the aircraft.

General Sir Charles Guthrie explains the significance of the attacks on the L29 project

Sir Charles said the hangar where around a dozen of the planes were based had been destroyed and Saddam Hussein's capability to wage war with chemical or biological weapons had been "severely dented".

Nick Cook, an expert on unmanned aircraft who works for the magazine Jane's Defence Weekly, described the L29 programme as a "desperate measure".

He said: "Crop-sprayers are necessarily low-flying planes, which could easily be shot out of the sky".

Robot jets of the future

More alarming, he said, could be the development of a second type of unmanned plane which uses a MiG 21 fighter jet.

Robertson coined term "drones of death"

The supersonic fighter, controlled by another MiG 21 in the vicinity, would be able to fly further afield and at far greater speeds than the crop-sprayer.

"We first heard they were being developed in an Unscom report about a year ago," he said.

"We then knew they were being developed, but not manufactured. It sounds like they've moved on a stage now."

But he said even the unpiloted MiG bomber was relatively unsophisticated, as it still requires a pilot in another aircraft nearby, and has a limited range.

"It really shows how far sanctions are forcing Saddam Hussein to live off his wits and come up with such weapons," he said.

Scientists in other countries, including the UK, USA and Israel are all working on developing pilotless reconnaissance aircraft.