By Michelle Nichols UNITED NATIONS (Reuters) – U.N. officials will investigate the killing and wounding of children in Ukraine, Ethiopia and Mozambique, U.N. chief Antonio Guterres said on Monday in a report that found 2,515 children were killed and 5,555 maimed in global conflicts in 2021. The annual “Children and Armed Conflict” report also verified the recruitment and use of 6,310 children in conflicts globally in 2021. Other violations it covers are abduction, sexual violence, school and hospital attacks and denial of aid. It found the highest number of verified violations against children…