Penal Code Section 148
Possessing weapons or missiles at riot
148. Any person who attends, takes part in or is found at any riot and who has in his possession at such riot any firearm, ammunition, explosive, corrosive, injurious or obnoxious substance, stick, stone or any weapon or missile capable of use as a weapon of offence shall be punished with imprisonment for a term which may extend to five years or with fine or with both.
Please refer to the Attorney General's Chamber of Malaysia's website for the latest law.