New Delhi, May 10 (IANS): A 42-year-old Delhi Transport Corporation (DTC) bus driver was beaten to death here on Sunday in a case of road rage, police said.

The driver, identified as Ashok, was beaten by a motorcycle rider after the bus he was driving hit the motorcycle from behind in Mundka area of west Delhi around 9.30 a.m.

A police officer said the motorcyclist and his mother, who was riding pillion, fell on the ground after being hit by the bus following which he entered into an argument with the bus driver.

The heated argument progressed to the motorcyclist beating up Ashok -- whom the former then left in an unconscious condition.

The biker left the spot before the police could reach there.

"The driver was rushed to a nearby hospital where doctors declared him brought dead. As per the driver's medical report, he has no external injury mark on his body. We are waiting for his postmortem report," the officer said.

The DTC bus was operating on an inter-state route -- from Karampura in west Delhi to Haryana's Bahadurgarh.

Police were yet to make any arrest in the case.