Border Security Force (BSF) troopers killed a Pakistani drugs smuggler and apprehended another early on Friday near the international border in Amritsar sector, a BSF spokesman said.Four kg of heroin, valued at Rs 20 crore, two Pakistani SIM cards and a mobile phone were seized during a search of the area.The spokesman said troopers noticed suspicious movement ahead of the border security fence at Ramkot. "The troopers challenged the smugglers as they tried to smuggle contraband items into Indian territory. They did not pay heed, following which troopers opened fire. One of them was killed and another arrested," he said.The arrested smuggler was being questioned by the BSF and other security agencies.Punjab shares a 553-km barbwired border with Pakistan.