Several children injured in the accident were seen lying by the roadside after rescuers came to their aid.
In another development, President Samia has sent a message of condolences to the bereaved families and wished the injured a quick recovery.
In a tweet, she wrote: I am saddened by the deaths of 8 pupils of King David primary school and 2 adults that happened this morning in Mtwara- Mikindani after their school bus plunged into a ditch. I offer my condolences to the bereaved, the Regional Commissioner and relatives. May Allah have mercy on the deceased and heal the injured.