Règle correspondante
Spain
Practice Relating to Rule 161. International Cooperation in Criminal Proceedings
Section B. Extradition
Spain’s LOAC Manual (1996) provides:
The States have the obligation to search for persons accused of having committed, or having ordered to be committed, grave breaches, being obliged to make them appear before their own tribunals, regardless of their nationality. They can also agree to the extradition of those persons in order for them to be judged by other States, in accordance with the legal obligations which regulate the said extradition. 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, § 11.8.b.(1).
The manual adds: “States shall provide each other with the greatest possible mutual assistance for the penal repression of violations, at national and international level. Such cooperation shall also be accorded in extradition matters.” 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Publicación OR7-004, 2 Tomos, aprobado por el Estado Mayor del Ejército, Division de Operaciones, 18 March 1996, Vol. I, § 11.8.b.(4).
Spain’s LOAC Manual (2007) states:
States have a duty to search for those suspected of having committed or having ordered others to commit grave breaches and try them in their own courts, regardless of their nationality. They can also extradite such persons to be tried by another State, provided that legal extradition requirements are met. 
Spain, Orientaciones. El Derecho de los Conflictos Armados, Tomo 1, Publicación OR7–004, (Edición Segunda), Mando de Adiestramiento y Doctrina, Dirección de Doctrina, Orgánica y Materiales, 2 November 2007, § 11.7.b.
In 2010, in the Couso case, which concerned the killing of a Spanish journalist in Baghdad on 8 April 2003 by troops of the United States of America, the Criminal Chamber of Spain’s Supreme Court referred to norms of IHL relevant to the case under review, including Article 146 of the 1949 Geneva Convention IV on the obligation to prosecute or extradite persons responsible for grave breaches. 
Spain, Supreme Court, Couso case, Judgment, 13 July 2010, Section II(II), Sexto, § 2, p. 13.
In 2010, in its report of 23 July, Spain’s Council of Ministers stated:
Extradition to Bosnia of Veselin Vlahovic for crimes against humanity
The Council of Ministers has approved the surrender in extradition to Bosnia and Herzegovina of Veselin Vlahovic, for crimes against persons and property protected in the event of armed conflict.
Vlahovic’s extradition is sought for having committed grave crimes against humanity during the war in Bosnia and Herzegovina between 1992 and 1995. He has been accused, as a member of the armed forces of the República Srpska, of terrorising the population of Grbavica (Sarajevo), persecuting the civilian population of non-Serb origin, personally killing a large number of people, committing pillage, rape, abuses, torture and other crimes.
The European Convention on Extradition of 13 December 1957 applies to Vlahovic, who is being held on remand in custody. 
Spain, Ministry of the President, Council of Ministers, Report, 23 July 2010, p. 61.
In 2010, in its report of 1 October, Spain’s Council of Ministers stated:
Continuation of the proceedings for the extradition to Bosnia of Veselin Vlahovic
The Council of Ministers has approved the continuation of the proceedings for the first extension of the passive extradition of the Montenegrin citizen Veselin Vlahovic, requested by the authorities of Bosnia and Herzegovina.
[Vlahovic] is suspected of having committed grave crimes against humanity during the war in Bosnia and Herzegovina as a member of the armed forces of the República Srpska, between 1992 and 1995. Concretely, the new facts state that in 1992 [Vlahovic], together with other members of the so called “White Angels”, took fifteen members of a family to a Jewish cemetery in Novo Sarajevo where they were machine gunned, including among those killed a boy of six and a woman. In July of the same year, in Grbavica he removed a couple from their home and killed them both.
The facts described constitute a war crime against the civilian population under the Criminal Code of Bosnia and Herzegovina, which constitutes a crime against persons or property protected in the event of armed conflict under the Spanish Penal Code in force.
[Vlahovic]’s extradition was also requested by the Serb authorities, for the crime of murder and by the Montenegrin authorities for the crime of violent robbery and war crimes.
The surrender of Veselin Vlahovic is proposed, in the first instance, to the authorities of Bosnia and Herzegovina as the European Convention on Extradition of 1957 applies to all three requesting States, because the crimes committed by [Vlahovic] in Bosnia and Herzegovina are both quantitatively and qualitatively of relatively greater gravity. This State sent a request for extradition through the diplomatic channel on 8 March 2010, before the other two States. The extradition took place on 25 August 2010. 
Spain, Ministry of the President, Council of Ministers, Report, 1 October 2010, p. 41.
In 2011, in its report, Spain’s Council of Ministers stated:
Extension of extradition to Bosnia of Veselin Vlahovic for crimes against humanity
The Council of Ministers has approved the continuation of the procedure for the second extension of the extradition to Bosnia and Herzegovina of Veselin Vlahovic, accused of committing grave crimes against humanity during the war in Bosnia and Herzegovina from 1992–1995.
The second extension of the extradition requested by the authorities of Bosnia and Herzegovina for prosecution refers to facts not included in the original request. They now claim that he is suspected of having carried out in Sarajevo (Bosnia), between April and June 1992, together with other members of the so called “White Angels” acts against the non-Serb civilian population including kidnapping, extortion, threats, thefts, injury, rapes and murders.
On 25 August 2010 he was surrendered to the authorities of Bosnia and Herzegovina for a previous extradition request.
The acts described constitute the crime of war crimes against the civilian population under the Penal Code of Bosnia and Herzegovina, which corresponds to the crime against protected persons and property in the event of armed conflict under section 607 onwards of the Spanish penal code in force. 
Spain, Ministry of the President, Council of Ministers, Report, 11 February 2011, p. 21.