The van was carrying students to the Government Public School Fateh Pur in Layyah, some 350 kilometres from Lahore, when a speeding truck coming from opposite direction collided with it, rescue officials said.
More than 10 children who were inside the van suffered fatal injuries. They were shifted to local hospital where six of them succumbed to their injuries while the condition of four others remain critical.
The driver of the van also died in the accident.
A rescue official said the accident was caused by over speeding of the truck driver despite fog.
Police have registered a murder case against the driver. However he was not arrested.