Indian police will start using pepper-spraying drones to control unruly crowds of protesters. Officials described the drones as a "non-lethal but very effective" method of "mob control."

According to AFP, police in the north Indian city of Lucknow, which has a population of two million, have already successfully trialed the aircraft and given them the thumbs-up.

The results of the tests were "brilliant" according to Lucknow police chief Yashasvi Yadav. "We have managed to work out how to use it to precisely target the mob in winds and congested areas. Pepper is non-lethal but very effective in mob control. We can spray from different heights to have maximum results.”

The city’s police force has bought five of the paper-spraying drones at a cost of around 600,000 rupees ($9,650), with plans for them to go airborne by the end of April.

The unmanned aircraft can be flown within a one-kilometer radius of their operator and carry two kilograms of pepper onboard. They are also equipped with high-resolution cameras to surveil their targets.

Lucknow, India's eighth most populous city, has previously used drones to monitor crowds during religious festivals, but its use of pepper spray is a first.

"We have purchased five drone cameras with capacity of lifting 2 kg weight. They can be used to shower pepper powder on an unruly mob in case of any trouble," Yadav told India's news agency PTI. He said the drones would be used "throughout the city for aerial surveillance."

This story originally appeared on Wired UK.