The accident happened on December 18 in the Frunzensky district of the city.
The passenger bus drove off the road and crashed into cars parked in the courtyard of a residential building.
"The Investigation Department for the Frunzensky District of the city of Saratov ... organized a pre-investigation check on the fact of a traffic accident involving a passenger bus," the regional department of the Investigative Committee of Russia said in a statement.
Earlier it became known about a major accident in the Khabarovsk Territory - as a result of a collision of a bus with a heavy cargo, six people were injured, including two children.
According to preliminary information, a five-year-old boy received a brain concussion, a nine-year-old - a bruised shoulder.