50. If any person-(a) obstructs or molests any person with whom the Authority has entered into a contract in the performance or execution by such person of his duty or of anything which he is empowered or required to do by virtue or in consequence of this Ordinance or any rule made thereunder; or(b) removes any mark set up for the purpose of indicating any level or direction necessary to the execution of work authorised by this Ordinance or any rule made or development scheme approved thereunder,he shall be punishable with imprisonment for a term which may extend to six months, or with fine which may extend to Taka one thousand.