The collision between the auto and the Patna-bound bus coming from Sitamarhi took place in Jhapha village near a CRPF camp, Senior Superintendent of Police Vivek Kumar said.
While nine persons died on the spot, one succumbed to injuries in the hospital, the SSP said.
The injured were admitted to Sri Krishna Memorial College and Hospital (SKMCH).
The deceased minors were in the age group of one month to two years.