The Border Security Force (BSF) has recovered 15 kg of heroin along the India-Pakistan border in Punjab's Tarn Taran sector, officials said on Tuesday.The heroin was recovered after exchange of fire between smugglers from the Pakistan side and BSF troopers early on Tuesday.The seizure was made in the Khem Karan area of Tarn Taran sector.BSF officials said that BSF troopers had noticed suspicious activity of smugglers near the border fence. The smugglers were trying to throw packets containing heroin over the fence. When the smugglers were challenged, they fired at the BSF personnel. The BSF personnel retaliated but the smugglers, taking advantage of darkness and wild growth, managed to escape. Following a search on Tuesday, the BSF also recovered the heroin consignment from the area.The seized heroin is valued at Rs 75 crore in the international market.