20 No. 21 Prevention of Terrorism 2002 (2) It shall be a defence for a Person charged with an offence under this section to Prove that the entity in respect of which the charge is brought was not a terrorist group at or on the date that he (a) became a member of, or (b) Professed to be a member of, that entity, or- that he has not taken part in the activities of that entity, after it became a terrorist group. Arrangement of meetings in support of terrorist groups 26.-(1) Every person who arranges, manages or assists in arranging or managing a meeting which he knows is(a) to support a terrorist group; (b) to further the activities of a terrorist group, (c) to be addressed by a person who belongs or professes to belong to a terrorist group, is guilty of an offence and shall on conviction be liable to imprisonment for a term not less than ten years and not more than fifteen years. (2) In this section ''meeting'' means a meeting of three or more Persons, whether or not the public are admitted. Participation in the commission of offences under this Act 27. Every person who-(a) aids and abets the commission; (b) attempts to commit; (c) conspires to commit; (d) counsels Or Procures the commission of, an offence under this Act, is guilty of an offence and shall on conviction, be liable to the same punishment as is prescribed for the first mentioned offence. PART V INVESTIGATION OF OFFENCES Powers of arrest 28,-(1) Any police officer may arrest without warrant any Person who has committed or is committing or whom he has reasonable grounds for suspecting to have committed or to be committing an offence under this Act. (2) For the purposes of subsection (1), "police officer'' means and include a police officer of or above the rank of Assistant Superintendent, an immigration officer or a member of Tanzania intelligent security service.