The truck was carrying iron rods on which 34 labourers were sitting, police said, adding that the driver lost control of the truck while he was trying to avoid a speeding bus coming from the opposite direction on the national highway (NH) 59.
"The truck broke the railings and fell into a 20-feet deep roadside ditch. Four persons died on the spot while 25 others were grievously injured after they fell in the ditch and were hit by the iron rods," he said.
The deceased are yet to be identified, police said, adding that they were probably coming from Rajasthan.
A complaint has been lodged in Dahod rural police station for further investigation, said the officer.