The victims were passengers of a private luxury bus, which was heading towards Navsari in south Gujarat from Deesa town of Banaskantha district.
As the bus reached on the Expressway at Vanthwadi village under Mahemdavad taluka in Kheda, its driver Bipin Hariyani stopped the vehicle at a roadside to check the air pressure of tyres, police inspector R I Solanki said.
"When he was checking the tyres, a truck rammed into the bus from behind as the truck driver didn't see the bus due to darkness. The impact was mild. Some passengers then got down from the bus after learning about the verbal spat between their driver and that of the truck," he said.
"Four passengers were crushed to death under the front wheels of the stationary truck while six other passengers received injuries," the police officer said.
"We have lodged a case against the driver of the mini-truck and started further investigation," he said.
The deceased have been identified as Nasir Bambawala (48), a resident of Ahmedabad, Prabhu Prajapati(23), Parbat Harijan(23), and Mahetusinh Thakor(18), all residents of Deesa taluka of Banaskantha district, police added.