Hostages

Some background info:

International Convention Against the Taking of Hostages
ARTICLE 1

1. Any person who seizes or detains and threatens to kill, to injure or to continue to detain another person (hereinafter referred to as the "hostage") in order to compel a third party, namely, a State, an international intergovernmental organization, a natural or juridical person, or a group of persons, to do or abstain from doing any act as an explicit or implicit condition for the release of the hostage commits the offence of taking of hostages ("hostage-taking") within the meaning of this Convention.
2. Any person who:
1. attempts to commit an act of hostage-taking, or
2. participates as an accomplice of anyone who commits or attempts to commit an act of hostage-taking likewise commits an offence for the purposes of this Convention.

Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts, 8 June 1977.Protocol I, Art. 75

2. The following acts are and shall remain prohibited at any time and in any place whatsoever, whether committed by civilian or by military agents: (a) violence to the life, health, or physical or mental well-being of persons, in particular: (i) murder; (ii) torture of all kinds, whether physical or mental; (iii) corporal punishment; and (iv) mutilation;

(b) outrages upon personal dignity, in particular humiliating and degrading treatment, enforced prostitution and any form or indecent assault; (c) the taking of hostages; (d) collective punishments; and (e) threats to commit any of the foregoing acts.

Convention IV, Art. 147
Art. 147. Grave breaches to which the preceding Article relates shall be those involving any of the following acts, if committed against persons or property protected by the present Convention: wilful killing, torture or inhuman treatment, including biological experiments, wilfully causing great suffering or serious injury to body or health, unlawful deportation or transfer or unlawful confinement of a protected person, compelling a protected person to serve in the forces of a hostile Power, or wilfully depriving a protected person of the rights of fair and regular trial prescribed in the present Convention, taking of hostages and extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly.