(CNN) -- Sixteen children and a teacher in Pakistan were killed Saturday after a gas canister used to fuel a school minivan exploded on a hot spring day, police in Gujrat said.
The blast injured 10 other people, according to Nadeem Ulla, a local police official.
"It's over 100 degrees (38 degrees C), the heat probably caused the explosion," Ulla said. "We do not expect any foul play ".
Compressed natural gas is used as an alternative fuel to gasoline because the engines are more energy efficient and cheaper to run.