The Ansbach explosion is the third attack in the German state of Bavaria in a week.
A Syrian asylum-seeker's been arrested after killing a woman with a machete in the South-west city of Reutlingen.
While nine people died on Friday in Munich when they were targeted by a gunman, who later shot himself.
A 16-year-old boy,has since been arrested on suspicion of failing to report plans for the fatal shooting.
Clint Schmidt knew the suspect, as well as one of the youngsters injured:
