Africa News Tonight: Al-Shabab militants in Somalia today attacked a military base housing Ugandan forces of the African Union peacekeeping mission. Witnesses say there is fierce fighting between rival Sudanese forces today in the western region of Darfur, although United States and Saudi Arabian observers noted "improved respect" for a fragile ceasefire now in its fourth day. And, Zimbabwe officials hope vaccinations will tame a cholera outbreak as citizens continue to drink unsafe water. For this and more, stay tuned to Africa News Tonight!