Four of the injured children and the van driver were reported to be in a serious condition, they said.
The children were on their way to Central School at Bharveli when the van driver lost control over wheels while trying to save a street dog from getting knocked down.
In the process, the van hit a tree and turned turtle at Aonla Jhiri village, around 5 kms from the district headquarters, an officer at Bharveli police station said.
The four seriously hurt students were admitted at a private hospital, while the 12 others were being treated at the district hospital here, he said.
The seriously injured van driver was rushed to Nagpur for treatment, the police officer said.
District Collector V Kiran Gopal and Superintendent of Police Gaurav Tiwari have rushed to spot after the mishap.