A heat ray gun developed by the US military has been withdrawn from Afghanistan, army chiefs have confirmed.

The Active Denial System (ADS) is a non-lethal weapon that heats up the skin "intolerably" but, according to tests, causes no permanent damage.

Its invisible beam is designed to repel enemies and disperse violent crowds, causing anyone targeted to immediately move away.

US military commanders in the country have had the weapon at their disposal but have now decided against using it.

The weapon was never actually deployed in a 'real life' scenario.

"The ADS was not used and was shipped from Afghanistan. The operational need for the device was not approved by commanders", confirmed Colonel Shanks, Chief of Public Affairs for ISAF.

The beam produced by the ADS can travel more than 500m (1,640ft) and is seen as a potential way to limit war zone fatalities in the future.

It's already been tested more than 11,000 times on around 700 volunteers, including journalists.

The US military says the chance of injury is 0.1% as the beam only penetrates the skin to the equivalent of three sheets of paper