According to Joint Commissioner of Police Sandeep Goel, the incident took place around 8.30 PM when about 500 to 700 protesters tried to block the main highway by-pass road, demanding scrapping of Civil Services Aptitude Test (CSAT).
“A police jeep was set on fire. One Roadways bus was partially burnt in the incident along with some bikes and cars.
Police used force to disperse them from main roads,” Goel said, adding, at least 10 policemen were injured in the incident.
Police resorted to use of tear gas and lathicharge to disperse the protesters.
Deputy commissioner of police (North) Madhur Verma said some Kanwariya pilgrims camping on the route helped police control the protesters.
Police have detained 20 protesters and charged them with rioting, damaging public property, preventing public servants from performing their duty and assault.
According to Delhi Fire services, a call was received about a police jeep being set on fire at 8:50 PM following which two fire tenders were rushed to the spot.
The situation is under control now and traffic on the route has been opened, police said.
Those detained in connection with the clash have later been arrested, said a police officer.