THE United Nations has painted bright orange its two white helicopters providing humanitarian relief in eastern Congo in an effort to protect them from militia attacks by distinguishing them from other aircraft. Insecurity has worsened in east Congo since a rebel group known as the M23 - one of many armed militias active in the region - launched a fresh offensive last year. Humanitarian operations to help the thousands of civilians displaced by the fighting have been caught up in the fighting. Last year, the U.N. recorded 293 security incidents that affected relief missions to east Congo, resulting in the…