CRC/C/CHN/CO/2 page 17 (c) Ensuring that re-education through labour does not result in children working in violation of the principles and provisions of ILO Conventions Nos. 138 and 182. Street children 85. While noting with appreciation the efforts of the State party in mainland China, the Committee is concerned at the significant numbers of children living and working in the streets. 86. The Committee recommends that in mainland China, the State party strengthen its efforts related to street children, in particular by: (a) Undertaking further research into the situation of children living and working in the streets, and using such research to develop appropriate programmes and policies to reduce the number of street children and provide them with appropriate assistance; (b) Prioritizing family- and community-based interventions aimed at reintegrating these children successfully into their families; (c) Increasing the resources provided to local authorities providing services to street children and their families. Sexual exploitation and trafficking 87. With respect to mainland China and the Macau SAR, the Committee notes with appreciation the submission of the initial report under the Optional Protocol on the sale of children, child prostitution and child pornography, and refers the State party to the relevant recommendations contained in its concluding observations thereon (CRC/C/OPSA/CO/2). The Committee regrets that the application of the Optional Protocol has not yet been extended to the Hong Kong SAR. While welcoming the amendments to the Crimes Ordinance aimed at strengthening the protection of children from pornography, it is concerned at the absence of any data on or reported cases of child prostitution in the Hong Kong SAR. 88. In order to prevent and combat trafficking in children for sexual and other exploitative purposes, the Committee recommends that the State party in the Hong Kong SAR: (a) Further develop and enhance systems of early prevention of sexual exploitation and trafficking; (b) Further strengthen its efforts to identify and investigate trafficking cases, to improve understanding of the issues of trafficking and ensure that perpetrators are prosecuted; (c) Develop and adopt a comprehensive policy to prevent and combat sexual exploitation and trafficking in children, including the root causes and factors that place children at risk of such exploitation;