A 21-year-old Pakistani national was arrested when he intruded into the Indian territory from across the International Border (IB) here, officials said on Sunday.Saber Nawaz, a resident of Malik Chak, crossed into Akhnoor sector in the outskirts of Jammu on Saturday and was noticed by the alert Indian army guarding the border, the officials said.They said Nawaz was challenged and subsequently taken into custody.He was handed over to Khour Police station on Sunday for interrogation, the officials said.