WHY ATTACK FROM AIR WILL HAPPEN HERE

REPORTS of the attempted assassination of the Venezuelan president using a drone pose a grim question. Could Britain, where sophisticated drones are available from high street electronic stores or online for a few hundred pounds, be vulnerable to a similar attack, perhaps by a ‘lone wolf’ terrorist?

‘In security circles, it’s for some time been a question of “when” rather than “if” we see a drone strike in a civilian environment, and this [incident in Venezuela] looks like having been the “when”,’ according to Hamish de Bretton-Gordon, a former British Army officer and counter-terror expert.

Certainly, the expertise is out there. Last January, Harvard academic Vera Mironova discovered an extraordinary cache of documents in a captured Islamic State military workshop in the Iraqi city of Mosul.

Written in Arabic and English, they revealed a programme to turn radio-controlled drones – the kind of easily available off-the-shelf gadget – into killing machines that could carry and drop hand grenades.

The discovery proved what military intelligence had been saying for months: that these so-called ‘quad-copter’ drones were increasingly the jihadists’ battlefield weapons of choice. They were cheap, easy to use and capable of transporting a load of up to 4lb to a precise location several miles away with minimal risk to the operator.

Soon after Mironova’s discovery, the Iraqi government revealed there had been at least 80 attacks in the previous two months, usually involving drones with a plastic tube allowing them to drop 40mm rifle grenades that can kill or injure within a 16ft radius.

A dozen Iraqi troops had been killed and 50 injured. Countless other IS drone strikes were observed being carried on civilian refugees during the battle for Mosul last year.

Similar devices have been reported in Afghanistan, where extremists used them to launch unsuccessful strikes on the New Kabul Compound, a military base occupied by US and UK forces.

In January, Russian bases in north-west Syria came under a ‘swarm attack’ by 13 drones, simultaneously controlled using what appears to have been a GPS unit.

It is the growing frequency and sophistication of such attacks that have raised fears of similar tactics being used by terrorists far from major battlegrounds.

‘We know a lot of IS fighters have dissipated around the world, so the big concern is that they take what they have learnt with them and mount a drone attack in the West,’ said De Bretton-Gordon.

His biggest fear is that a sporting event or public gathering could be attacked by a drone carrying a substance such as chlorine Danger: An M600 drone of the kind said to have been used in Venezuela gas. ‘This may not kill many but the panic ensuing could be devastating,’ he said.

Part of the problem the security forces face is a sort of ‘arms race’ among largely Chinese manufacturers to produce ever more powerful and sophisticated devices at the lowest price.

Those most feared in security circles, according to De Bretton-Gordon, are the so-called ‘$500 drones’ capable of flying several miles at heights that make them hard to shoot with firearms or other conventional weapons. Some even come equipped with anti-jamming systems to evade efforts to disrupt their control systems.

‘Using drones would be part of what IS call the weaponisation of everyday life,’ said David Dunn, an expert in security policy at Birmingham University who first drew attention to the risk of terrorists using drones in 2012. ‘We’ve seen it with knives, trucks and rental cars. Their tactic is to take whatever is at hand and use it to mount an attack.’

Major public events are now protected with the help of military technology. When British and US troops at the New Kabul Compound came under drone attack last year, they defended themselves using AR-15 Drone Defenders.

These look like rifles but instead of firing bullets they send out radio waves that disrupt the signal controlling the drones so they drop to the ground. They have a range of more than 1,300ft and these and other devices could be used to create an ‘electronic cordon’ around Twickenham, Wembley or other venues for big events.

Meanwhile, experts advise regulating the drone market, for example by banning anti-jamming technology or insisting that all new models come equipped with GPS systems that could halt them in the vicinity of high-risk target areas.

But that still leaves gaps in our defence. ‘As the Salisbury Novichok attack shows us, it’s all very well policing a big event or a scheduled appearance by the royals, but that still leaves endless unexpected targets,’ said one source. ‘A lot of people are working very hard to keep us safe, but nothing will ever keep us 100 per cent safe.’