A/HRC/42/CRP.1 old; one woman and two men). In addition, eight persons were injured, including two men, two women, two girls, and one boy. Information gathered by the Group of Experts indicates that the neighbourhood was a quiet residential area, with two functioning schools in front of the targeted building. The strike occurred during Ramadhan when many of the building’s residents were still sleeping. 443. The Group of Experts confirmed that civilian casualties occurred during this airstrike, and did not identify any apparent military targets in the area. (g) Violations 444. According to the principle of distinction, parties to the conflict must at all times distinguish between the civilian population and individuals participating in hostilities. Attacks may only be directed against the latter. Similarly, attacks may only be directed against military objectives. Civilian objects lose protection from attack if and for such time as they are used for military purposes.712 Should the parties target a military objective, they must respect the principle of proportionality in attack. According to this principle, an attack may not be expected to affect civilians or civilian objects in a way that would be excessive in relation to the anticipated military advantage.713 Finally, in line with the principle of precautions in attack, constant care must be taken to spare the civilian population and civilian objects in the conduct of military operations.714 445. Medical facilities are specifically protected under international humanitarian law. Along with medical personnel, medical units and transport must be respected and protected at all times.715 They must not be the object of attack, as long as they are not used to commit acts harmful to the enemy. In such case, they may become legitimate military objectives and lose their protection after the issuance of an unheeded warning. 716 Intentionally directing attacks against protected medical units is a war crime in non-international armed conflicts.717 446. In most cases described above, that is the airstrike close to the Kitaf Hospital in Sa’dah, the airstrike on the house and farm in Hajjah, and the airstrike on the residential building in Sana’a, there is nothing to suggest from the evidence at hand that there were military targets at the respective sites of the attacks or nearby. This raises concerns over the respect for the principle of distinction. 447. In the case of the Kitaf Hospital, in particular, the airstrike hit in the close vicinity of a hospital and a market, as should have been known to the coalition, at a busy time of the day, when civilians, including medical staff, were present. Even in the event a military target was present, the location and the time of the strike raise concerns with regard to the coalition’s respect for the principles of proportionality and precautions in attack. 448. With regard to the airstrike in Hajjah, the number of airstrikes, their timing, their proximity to each other (less than 10 minutes lapse), the damage done to the houses and the fact that the last one hit an open area that women and children were running into, suggest that the second and third airstrikes may have been ordered without an adequate assessment of the targets, in violation of the principle of distinction. Even if the first house had been considered as a legitimate target, there are concerns that the coalition may have failed to respect the principle of proportionality and to take the necessary precautions to minimise civilian harm. The same concerns as regards the principle of distinction and precautions are valid for the attack on the residential building in Sana’a, given its location in a residential neighbourhood, in front of two functioning schools. 712 See ICRC Study on customary IHL, rules 1 to 10 in particular. See also Article 13 Additional Protocol II. 713 See ICRC Study on customary IHL, rule 14. 714 See ICRC Study on customary IHL, rule 15. 715 See ICRC Study on customary IHL, rules 28 and 29. 716 Article 11 Additional Protocol II; see ICRC Study on customary IHL, rules 28 and 29. 717 Article 8(2)(e)(ii) and (iv), Rome Statute. 111