KIGALI, Rwanda   US senators raised concerns over the ongoing occupation of parts of eastern Democratic Republic of Congo by the M23 rebel group during a meeting with President Felix Tshisekedi, according to a statement. The M23 rebel group has been at the center of the conflict in eastern DR Congo. Allegedly backed by neighboring Rwanda, according to the United Nations and Western nations, the group controls significant territory in the region, including the provincial capitals of Goma and