Britain could be at risk of falling victim to a terrorist attack from using swarm drones, say experts.
"If you have relatively simple technologies, actually anyone can put together one of these 'DIY drones' and that's what's really worrying about it", Sebastian Brixey-Williams, the Programme Director at BASIC, said.
The US Department of Defense dropped 103 “micro drones” out the back of three military fast jets over a test site in California, in October 2016.
Weighing just less than 300 grams each and with a wingspan of only 30 centimetres, the US says they demonstrated advanced swarm behaviors such as collective decision-making, adaptive formation flying and self-healing.
But experts are concerned about what could happen if this technology got into the hands of terrorists.
"There have been attacks in ISIS held territory where they've dropped bombs from drones," Mr Brixey-Williams, said.
"A Russian air based was attacked by a fleet of drones, last year, and they don't know who did that."
In the UK, Gatwick Airport was completely shut down after suspected drone sightings around the airport during the Christmas period.
"We're all vulnerable to these technologies", Mr Brixey-Williams said.
Under scrutiny from a cross-party group of MPs, the policy director of the Civil Aviation Authority, Tim Johnson, said a new system to regulate private owners of drones would not tackle unlawful use.