(2) Any person summarily convicted for a second or subsequent offence against this Act is liable to a fine of not less than $500 and not exceeding $3,500 or to imprisonment for a period of not less than 6 months and not exceeding one year or both. However, where any conviction is made under section 14(4) of the Act and such hindering, obstruction, molestation or assault is by use of weapons such as knives, cutlasses, firearms or other instruments the penalty shall be imprisonment with hard labour for a period not less than one year.