The Border Security Force (BSF) seized 18 kg of heroin worth Rs 90 crore in the international market, which was smuggled from Pakistan, in the Khemkaran sector here today.The paramilitary force also recovered a pair of Pakistan-made shoes from the spot.Around 5.15 am, suspicious movement of miscreants was observed near the International Border (IB), said Anant Singh, Commandant Officer (CO) of the 87th Battalion of the BSF.The officer said the patrolling party of the BSF saw two Pakistani smugglers sending some packets through a PVC pipe from across the fence who returned after committing the task of sending the packets.A search operation was carried out by a BSF party and 18 packets of contraband, Pakistan-made plastic pipe and a pair of shoes were recovered near Karnail Singh Wala BOP, he said.Anil Paliwal, Inspector General of BSF, Punjab Frontier, has issued operational guidelines to all sectors under the frontier to further strengthen border security.RK Thapa, BSF DIG of Ferozepur sector, has directed field commanders to maintain extra vigil on the border to thwart the attempts of anti-national elements. Tactical operations are being mounted to foil the attempts of the smugglers, the officer said.