A female intruder was killed by border security force (BSF) troops at the International Border (IB) in Akhnoor sector here, police said.According to police, troops of 33 battalion of the BSF on Thursday night killed the intruder near Chak Phagwari border outpost."The intruder was repeatedly challenged, but she ignored all warnings and crossed into the border. Troops then fired to foil the intrusion," police said.According to BSF sources, the troops could not distinguish the intruder's gender in darkness and had to fire as he ignored all warnings.