Beware of ‘vultures’ in the air

A device that can block wireless signals being tested in Bogota, Colombia. (Below) Employees testing devices designed to neutralise drones. — Federico Rios Escobar/The New York Times

COLOMBIAN soldiers defending a state-owned oil pumping station near the border with Venezuela were under attack. Two powerful insurgent groups that have been fighting the Colombian state for decades had been regularly stealing fuel from it.

The soldiers were used to snipers and ambushes, but now they had to contend with a new weapon their adversaries have by the thousands: swarms of small drones, the kind hobbyists can buy on Amazon, fitted with clawlike hooks carrying grenades.