British soldiers in Afghanistan have become the first to use miniature surveillance helicopters in frontline operations.
The drones can fly around corners and obstacles to identify potential hidden dangers, the Ministry of Defence said.
The Norwegian-designed Black Hornet Nano features a tiny camera and relays video and still images to a handheld control terminal.
It measures about 10cm by 2.5cm (4in by 1in) and weighs 16g (0.6oz).
The MoD, which also operates more than 300 larger-sized unmanned air vehicles in Afghanistan, said the Black Hornet is carried easily on patrol and works in harsh environments and windy conditions.
They have been in use in Afghanistan since 2012, a spokeswoman confirmed.
Surrey-based Marlborough Communications has a £20m contract with the military to supply and maintain 160 of the drones, which were originally developed by Prox Dynamics for search and rescue operations.
Mini drones can be piloted directly or programmed to follow co-ordinates using GPS.
Powered by battery, the Black Hornet is reported to have a range of about half a mile (800m), a top speed of 22mph (35kph) and can fly for up to 30 minutes.
They can help soldiers on the ground pinpoint hidden Taliban fighters and explosives.
Sgt Christopher Petherbridge, of the Brigade Reconnaissance Force in Afghanistan, said: "We used it to look for insurgent firing points and check out exposed areas of the ground before crossing, which is a real asset.
"It is very easy to operate and offers amazing capability to the guys on the ground."
Defence minister Philip Dunne said intelligence, surveillance and reconnaissance systems were a "key component" of the MoD's investment in new equipment over the next 10 years.
Spending outlined last month also includes almost £36bn for a new generation of nuclear-powered submarines, almost £19bn for combat aircraft, and around £17bn for Royal Navy warships.