A woman was killed and three persons were injured in a blast that rocked a house in Swat's Tehsil of Kabal on Sunday morning. The blast occurred at the house of Roshanzada, who is member of local Peace Committee in Kabal area of Sangarserai, killing a woman and injuring three others including Maher (14), Dilshad (15) and Ismail. The nature of the blast could not be ascertained immediately. The injured have been shifted to a local hospital. Police said all the injured are out of danger. The relief activities could not be carried out smoothly as it is a far-flung area. The security forces cordoned of the whole area.