Mínimum criteria in deprivation of liberty An urgent renovation of these facilities is considered necessary given their state of maintenance and upkeep. Signing room at the centre of Motril (Granada) 367. Detention at these facilities, with an average duration of 48 hours, is particularly hard for those groups that need most protection and whose protection should be a priority, such as minors and pregnant women. Attention must be brought to this matter and to the need to prepare a specific protocol for these groups. 368. As a general rule, the measure of deprivation of liberty is adopted while the necessary arrangements or actions are carried out after these persons arrive to the coast. The NPM considers that other alternatives should be explored. 369. The United Nations Convention on the Rights of the Child establishes that the deprivation of liberty of a minor should be a measure of last resource and for the shortest possible period. The alternative to detention in a police station or similar facilities, such as first aid resources, would be to stay in centres for humanitarian shelter. If the alternative measures cannot be adopted, the non-applicability of the less restrictive options should be founded, and it should be evidenced that the deprivation of liberty is ordered in the best interest of the minor. 370. Such alternatives should likewise apply to pregnant women or women with children, who should not be detained other than in few founded exceptions. 371. It is a priority that, in cases of minors accompanied by their parents, the best interest of the child should imply, rather than detention of the family, the preservation of the family unit without using a measure of deprivation of liberty. 117