Gurugram, June 22 (Reporter) At least eight persons were killed and several others injured in a blast at a fire-extinguisher manufacturing factory in Daulatabad industrial area of Gurugram, Haryana police and fire brigade sources said Saturday. According to the assistant fire officer, the fire brigade got information about the blast around 2.45 am after the fire had already spread to surrounding factories. More than 10 fire engines were rushed to the spot. Police have filed a case against factory owners and managers. Injured were rushed to nearby hospitals...////...