According to the police, Head Constable Raghuraj Singh sustained serious head injury while two other constables received minor injuries in the incident at Jamia Nagar yesterday.
"One Babar and his friend Majeed hit one Imran who was on his bike. They assaulted him and also hurled abuses at him. However, the matter was resolved after the victim's brother and bystanders intervened," a senior police officer said.
"But a few minutes later, Babar along with his friends came back and thrashed Imran. When Raghuraj Singh along with two constables reached the spot Babar and his friends pelted stones at them," he said.
Babar has been arrested while efforts are on to nab his accomplices. Two cases have been registered against them, police said.