Police said a school bus has driven into a ditch and flipped over in southern Germany, injuring 21 children, AP reported. Police in the Bavarian town of Straubing said four of the children and the bus driver were seriously hurt. Two of the students were taken to a hospital by helicopter but none of the injuries was thought to be life-threatening. The bus was carrying 43 students aged between 6 and 16. Police say it was going around a curve when the driver apparently got distracted and lost control.