The locals called the Police Control Room (PCR) and the victims were rushed to a nearby hospital.
According to a senior police officer, the dumper jumped hit the car with nine passengers aboard. They on their way to Meerut from the airport. The driver fled the spot.
A Delhi Fire Service official said four of the dead were related and the fifth victim was the driver.
The driver of the dumper with a Haryana registration number apparently lost control over the vehicle and it broke the divider hitting the SUV on the other side of the road, police said.
A hunt is on for the driver, police said. "We are investigating to determine the exact sequence of events," the officer added.
(With inputs from agencies)