"The bus was carrying students of the Delhi Public School (DPS) when it collided with the truck at Kanadiya bypass. Five students and the bus driver were killed in the accident which occurred because of a steering failure," Harinarayan Chari Mishra, DIG (Indore), told PTI.
Photos from the accident site show the entire front end of the bus smashed due to the collision. A video shows two bodies lying next to the bus as locals try to revive them, but to no avail.
There were 16 children in the school bus; the injured have been admitted to a nearby hospital.
Additional Superintendent of Police Manoj Kumar Rai said the school bus was on its way to drop the students to their homes when the collision took place.
An enquiry into the accident has been launched by the state government and Madhya Pradesh Chief Minister Shivraj Singh Chouhan expressed condolences on Twitter.
Talking to the media, Minister for School Education Deepak Joshi said the government will fix responsibility on schools regarding the safety of students.
"The government had issued guidelines for schools after a school bus accident in Bhopal. We will fix responsibility on schools to ensure the safety of children."
Indore is about 170 kilometres from Madhya Pradesh's capital Bhopal.
(With Inputs from PTI)