It shall not, except in obedience to a rule, regulation or order made by the Administrator or by the Commissioner of Police, be incumbent on the Delhi police to prosecute for an offence punishable under section 97, section 104, sub-section (1) of section 113, section 114, section 119 or section 121 when such offence has not occasioned serious mischief and has been promptly desisted from on a warning being given.