Washington: Militant groups like Hezbollah and Daesh have learnt how to weaponise surveillance drones and use them against each other, adding a new twist to Syria’s civil war, a US military official and others say.

A video belonging to an Al Qaida offshoot, Jund Al Aqsa, purportedly shows a drone landing on Syrian military barracks. In another video, small explosives purportedly dropped by the Iran-backed militant group Hezbollah target Jabhat Fatah Al Sham, formerly known as Al Nusra Front.

A US military official, who spoke anonymously because he wasn’t authorised to discuss the matter publicly, said the US military is aware of the development. Commanders have warned troops to take cover if they see what they might have once dismissed as a surveillance drone, he said.

The head of the Airwars project, which tracks the international air war in Iraq, Syria and Libya, said the weaponised drones are clumsy but will scare people.

“There are a million ways you can weaponise drones — fire rockets, strap things in and crash them,” Chris Woods said. He added: “This is the stuff everyone has been terrified about for years, and now it’s a reality.”

The US military official couldn’t immediately authenticate the videos in question, adding that most of the incidents they are aware of involved weaponised drones that simply crash into their targets. But another former senior US military official who viewed the videos said there was nothing to suggest they were fake.

A number of militant groups in the Middle East, including Daesh, Jund Al Aqsa and Jabhat Fatah Al Sham, as well as Hezbollah and Hamas, have all released videos indicating that they have surveillance and reconnaissance drones. Syrian anti-government rebels and militias loyal to President Bashar Al Assad were also flying cheap quad- and hexacopters as early as 2014 to spy on each other.

The surveillance drones allowed those groups to collect data on enemy bases, battlefield positioning and weaponry and improve targeting.