When more than three armed persons form a band of robbers for the purpose of committing robbery in the highway, or kidnapping persons for the purpose of extortion or to obtain ransom, for any other purpose to be attained by means of force and violence, they shall be deemed highway robbers or brigands.
Persons found guilty of this offense shall be punished by prision mayor in its medium period to reclusion temporal in its minimum period if the act or acts committed by them are not punishable by higher penalties, in which case, they shall suffer such higher penalties.
If any of the arms carried by any of said persons be an unlicensed firearm, it shall be presumed that said persons are highway robbers or brigands, and in case of conviction the penalty shall be imposed in the maximum period.