Amritsar, Dec 1 (PT) The Border Security Force Wednesday said its troops fired on a drone along the India-Pakistan border in the Amritsar sector, forcing it to return.In an official statement, the BSF said its personnel opened fire after they heard the humming sound of the drone coming from the Pakistan side and entering into the Indian territory on the intervening night of November 30 and December 1."Suspecting the modus operandi of ANEs (anti-national elements) of smuggling through a drone, troops retaliated with fire in the direction of a humming drone to thwart their attempt."Further, troops heard the returning sound of the suspected drone to Pak territory after 10 seconds," it said."Immediately, the depth area was cordoned, Police was informed and all escape routes were chocked. During extensive search of the area, 01 black colour bag with a ring attached with thread sling to hold the bag was found in a farming field on own side of fence."Four packets of contraband suspected to be heroin (weight appx. - 3.660 Kg) were recovered from the bag," it said.Officials said drones have become one of the biggest challenges for security agencies as the anti-national elements have been using them for smuggling and other illegal purposes. PTI JMS CHS SUN TIR TIR