The councilor from ward number 116 of Vikaspuri East, Balbir Tyagi, and his brother Vikas were travelling from their home to Tilak Nagar today when the incident took place, police said.
While the brother duo were traveling in a Honda City car, the youths were in a Tata Ace tempo.
"The two vehicles bruised against each other at Vikas Kunj in Vikaspuri. This triggred an argument between the two groups. It grew intense and the four youths allegedly beat them up," a senior police official said.
Balbir, block head of BJP, and Vikas Tyagi are under observation at Deen Dayal Upadhyay Hospital, he said, adding the four youth have been arrested.
The accused have been identified as Rajesh, Amit, Gopal and Amit all of whom are aged between 21 and 25 years. They work in a transport company and were shifting household articles from one place to another.