KHYBER AGENCY: Four persons were killed and three others received injuries in explosive device blast incident took place inside a house here in Shakas area of tehsil Jamrud of Khyber Agency. The security official said that the explosive suddenly went off in the premises of house of Niaz s/o Khaksar, an Afghan national, residing there at rent. Four rooms and veranda of residency were demolished in the explosion, sources said. Immediately after a happen, the security agencies and Bomb Disposal Squad (BDS) rushed to the spot and cordoned off the whole area. They retrieved the wounded and injured under the debris, Khasadar sources said. The injured were taken to Peshawar hospital for medical aid. The deceased were identified as Asif, Abdullah, Zahidullah and Niaz Mohammad.