CAT/OP/27/1 rights and fundamental freedoms in the political, economic, social, cultural, civil or any other field. 19. The Committee on the Elimination of Discrimination against Women maintains that, although the Convention refers only to sex -based discrimination against women, a comprehensive interpretation of the Convention indicates that it also covers genderbased discrimination against women. Whereas the term “sex” refers to biological differences between men and women, the term “gender” refers to socially constructed identities, attributes and roles of women and men and the social and cultural meaning that society attaches to these biological differences, which result in hierarchical relationships between women and men and in the distribution of power and rights favouring men and disadvantaging women. This social positioning of women and men is affected by political, economic, cultural, social, religious, ideological and environmental factors and can be changed by culture, society and community. 12 20. The Committee on the Elimination of Discrimination against Women has emphasized that gender-based violence, which impairs or nullifies the enjoyment by women of human rights and fundamental freedoms, is discrimination within the meaning of the Convention. These rights and freedoms include the right not to be subject to torture or to cruel, inhuman or degrading treatment or punishment. Gender based violence — that is, violence that is directed against a woman because she is a woman or that affects women disproportionately — includes acts that inflict physical, mental or sexual harm or suffering, threats of such acts, coercion and other forms of deprivation of liberty. 13 21. In this context, the Subcommittee on Prevention of Torture considers that the principle of equality and non-discrimination encompasses both the prohibition of differential treatment when the latter is arbitrary and imposes a disadvantage on a woman or group of women that limits or nullifies the exercise of human rights and the recognition of differences when such recognition is a reasonable, necessary and proportionate means of achieving the effective enjoyment of human rights. IV. The situation of women deprived of their liberty 22. The Subcommittee has conducted over 20 regular visits to States parties during which it has gone to various places of deprivation of liberty, including prisons, police stations, centres for juvenile offenders, shelters and psychiatric hospitals. 23. It has on several occasions observed situations in which women deprived of their liberty have been subject to ill-treatment or even torture. A. Violence 24. In many of the countries that it has visited, the Subcommittee has been apprised of reports from women deprived of their liberty, including pregnant women, that they have been subject to ill-treatment and physical torture, particularly at the time of arrest and during investigations. 25. More frequently, such claims concern various forms of sexual violence, including sexual extortion, sexual abuse and even rape committed by police officers 12 13 4/9 General recommendation No. 28 of the Committee on the Elimination of Discrimination against Women on the core obligations of States parties under article 2 of the Convention (CEDAW/C/GC/28 and Corr.1), para. 5. General recommendation No. 19 of the Committee on the Elimination of Discrimination against Women on violence against women (A/48/37, chap. I), paras. 6 and 7. GE.16-00603