A/HRC/42/CRP.1 Violations 550. The principle of distinction prohibits indiscriminate attacks, i.e. attacks that are of such nature to strike military objectives and civilians or civilian objects without distinction.851 Attacks using a method or means of combat that cannot be directed at a specific military objective constitute indiscriminate attacks. 852 In order to give effect to the principle of distinction, parties to the conflict must also take precautions against the effect of attacks. Accordingly, they must, to the extent feasible, also avoid locating military objectives within or near densely populated areas.853 551. The Group of Experts investigated three cases as mentioned above in which it found reasonable grounds to believe that the Yemeni armed forces and affiliated UAE-backed armed groups fired shells that killed and injured civilian men, women and children and that damaged civilian property. Two of these shelling incidents took place in the context of heavy and immediate fighting, as the forces were carrying out an offensive to gain territory. These two incidents raise concerns that Yemeni armed forces and affiliated UAE-backed armed groups used weapons in an indiscriminate manner on heavily populated areas to help them gain territory while providing cover to advancing forces. The third incident happened when there was no fighting. In this case, the shells hit a densely populated civilian area that was relatively calm at the time of the attack. In addition to the indiscriminate use of weapons in civilian areas, in violation of the principle of distinction, this further raises concerns over the timing of the attack and whether all feasible precautions were taken to protect the civilian population against the effects of attacks. 552. In the cases detailed above, the Group of Experts found reasonable grounds to believe that the Yemeni armed forces and affiliated UAE-backed armed groups were responsible for shelling attacks that were indiscriminate in violation of the principle of distinction, and failed to take all necessary and feasible precautions to protect civilians. These acts may lead to individual criminal responsibility for the war crime of launching an indiscriminate attack resulting in death or injury to civilians. 854 (d) Shelling by undetermined perpetrators, 2 August 2018, al-Hawak district, alHudaydah 553. At around 16:00 hrs, three mortar shells landed on the main fish market in alHawak, al-Hudaydah governorate. Shortly afterwards, two more shells detonated at the entrance to the al-Thawrah hospital, and a third struck the roof of the hospital records room. Two ambulances were hit by the second round of mortar shells. In total, the attack killed at least 41 civilians, including six children and four women, and injured 111 others, among them 19 children and three women. 554. The Group of Experts could not establish definitively what the intended target of the attack may have been. However, it received unconfirmed information that the Houthis had established a military post near the fish market allegedly containing “howitzer” pieces of artillery aimed at the coast. 555. The analysis of the craters left by the shelling in the street near the hospital indicated that the weapons were fired from the south. As the mortars that landed in the area near the hospital came from the south, and considering the reported presence of a Houthi military post in the area where the shells landed, the Group considers that it is probable the mortars came from the Airport, where the Yemeni armed forces and affiliated UAE-backed groups were based. 556. The weapon used appears to be a 120 mm mortar. Yemeni armed forces and affiliated UAE-backed groups and Houthi fighters all have 120mm mortars in their arsenals. However, the kind of shells seen in available pictures is a Rheinmetall Denel Munition, which is mainly available to the coalition. The Houthis, however, could have 851 Article 13(2) Additional Protocol II; See ICRC Study on customary IHL, rules 11-12. See ICRC Study on customary IHL, rule 12. 853 See Article 13(1) Additional Protocol II and ICRC Study on customary IHL, rule 23. 854 See ICRC Study on customary IHL, rule 156. 852 134