(c) Producing, distributing, disseminating, importing, exporting, offering, selling or possessing for the above purposes child pornography as defined in article 2. 2. Subject to the provisions of the national law of a State Party, the same shall apply to an attempt to commit any of the said acts and to complicity or participation in any of the said acts. 3. Each State Party shall make such offences punishable by appropriate penalties that take into account their grave nature. 4. Subject to the provisions of its national law, each State Party shall take measures, where appropriate, to establish the liability of legal persons for offences established in paragraph 1 of the present article. Subject to the legal principles of the State Party, such liability of legal persons may be criminal, civil or administrative. 5. States Parties shall take all appropriate legal and administrative measures to ensure that all persons involved in the adoption of a child act in conformity with applicable international legal instruments. Article 4 1. Each State Party shall take such measures as may be necessary to establish its jurisdiction over the offences referred to in article 3, paragraph 1, when the offences are commited in its territory or on board a ship or aircraft registered in that State. 2. Each State Party may take such measures as may be necessary to establish its jurisdiction over the offences referred to in article 3, paragraph 1, in the following cases: (a) When the alleged offender is a national of that State or a person who has his habitual residence in its territory; (b) When the victim is a national of that State. 3. Each State Party shall also take such measures as may be necessary to establish its jurisdiction over the aforementioned offences when the alleged offender is present in its territory and it does not extradite him or her to another State Party on the ground that the offence has been committed by one of its nationals. 4. The present Protocol does not exclude any criminal jurisdiction exercised in accordance with internal law. Article 5 1. The offences referred to in article 3, paragraph 1, shall be deemed to be included as extraditable offences in any extradition treaty existing between States Parties and shall be included as extraditable offences in every extradition treaty subsequently concluded between them, in accordance with the conditions set forth in such treaties. 2. If a State Party that makes extradition conditional on the existence of a treaty receives a request for extradition from another State Party with which it has no extradition treaty, it may consider the present Protocol to be a legal basis for extradition in respect of such offences. Extradition shall be subject to the conditions provided by the law of the requested State. 3. States Parties that do not make extradition conditional on the existence of a treaty shall recognize such offences as extraditable offences between themselves subject to the conditions provided by the law of the requested State. 4. Such offences shall be treated, for the purpose of extradition between States Parties, as if they had been committed not only in the place in which they occurred but also in the territories of the States required to establish their jurisdiction in accordance with article 4. 5. If an extradition request is made with respect to an offence described in article 3, paragraph 1, and the requested State Party does not or will not extradite on the basis of the nationality of