Islamic State has circulated designs for DIY anti-aircraft missiles, fuelling fears that they will be used to shoot down airliners in revenge for military action against it in Iraq and Syria.
The detailed plans include mobile phones which are installed inside the projectiles and are used to steer them to their targets.
A guide to building the guidance system is outlined in a video posted to YouTube and links to it have been distributed on a website linked to ISIS.
The high definition production had clocked up 10,206 views, suggesting that multiple cells in the West may already working on the devices.
It is produced in Arabic and is entitled: “Islamic State anti-aircraft missile manufacturing”.
The 35-minute video explains in detail how to build the system, which enables the weapon to home in on its target autonomously.
The comments below the video included expressions of good luck to the builders and attracted a reply from an apparent ISIS commander with the user name “minister of war”.
One user suggested that the missile should be used to extract revenge for the current military assault on ISIS’s Iraq HQ in the country’s second city of Mosul.
He said: “Their graveyard will be in Mosul and the walls of Mosul, God willing.”
Some even suggested making certain improvements to the design to increase its effectiveness.
The emergence of the plan is believed to be linked to difficulties encountered by ISIS in obtaining commercial shoulder-launched anti-aircraft missiles.
Western intelligence agencies are thought to have worked hard to ensure that obtaining them on the black market is extremely difficult.