The Punjab government on Saturday launched a major crackdown against radical Sikh preacher and Khalistan sympathizer Amritpal Singh, with police arresting 78 members of an outfit headed by him, officials said. The elusive preacher himself, however, gave the police a slip and escaped their dragnet when his cavalcade was intercepted in Jalandhar district, even as authorities stepped up security at several places and suspended internet and SMS services in the state till Sunday noon.