A captain and a sepoy of the Pakistan Army were martyred on Sunday while two others were injured in an exchange of fire with terrorists in Waziristan. According to a statement issued by the Inter-Services Public Relations (ISPR), security forces were patrolling the area five kilometers south-east of Ghariom near the boundary between North and South Waziristan when terrorists opened fire on them. Captain Mohammad Sabih Abrar and Sepoy Naveed Akhtar were killed in the exchange of fire while two other soldiers were injured. One terrorist was also killed, the statement added. The army troops later cleared a nearby militant compound in North Waziristan, said the ISPR. The latest attack came as authorities prepared to reopen a key border crossing with neighbouring Afghanistan to allow trade. Trucks carrying fruits, vegetables and other items will start crossing the Ghulam Khan border in North Waziristan district on Monday. Last month, two soldiers were martyred in a rocket attack on a security checkpoint in North Waziristan tribal district. The rocket, fired from an unknown direction, slammed into the checkpoint in Edek village, near Mirali town, around midnight. In April, 10 security personnel were martyred in attacks by militants in North Waziristan district while six suffered injuries.