In a joint operation with Punjab Police, the Border Security Force (BSF) seized eight kg of heroin in Punjab's Gurdaspur sector on Friday, a BSF officer said.Based on information from Punjab Police, the joint operation was launched near the border fence in Thakurpur where eight packets of heroin were found, BSF Deputy Inspector General R.S. Kataria said.The heroin is worth Rs 40 crore in the international market. The border with Pakistan in Gurdaspur district is about 275 km from here.Punjab shares a 553-km barbed-wire fenced border with Pakistan.