21. If any person carrying any gun, pistol, bowie-knife, dagger, or other dangerous weapon, to any place of worship while a meeting for religious purposes is being held at such place, or without good and sufficient cause therefor, shall carry any such weapon on Sunday at any place other than his own premises, shall be fined not less than twenty dollars. If any offense under this section be committed at a place of religious worship, the offender may be arrested on the order of a conservator of the peace, without warrant, and held until warrant can be obtained, but not exceeding three hours. It shall be the duty of justices of the peace, upon their own knowledge, or upon the affadavit of any person, that an offence under thiss ection has been committed, to issue a warrant for the arrest of the offender.