Mortar shells fired from an unidentified source hit two houses in Khyber Agency on Tuesday, leaving six people dead, including four children and a woman. The incident occurred in Bara sub division of the agency. Official sources said several mortar shells were fired from an unidentified area that hit two houses in Shalobar area. Local sources told to Pakistan Today that several shells landed in other areas as well, but casualties were so far not reported. The political administration has started investigating the matter.