(2)No prohibition under this section shall remain in force for more than three months:Provided that if the State Government consider it necessary so to do for the preservation of the public peace or public safety or for the maintenance of public order, they may, by notification, direct that the order issued under subsection (1) shall remain in force for such further period not exceeding six months from the date on which such order would have, but for such notification, expired, as they may specify in the said notification.