"Vigilantes taking up issues related to cow or love affairs should not be allowed to take law in their hands. Strict action should be initiated if any such case comes to fore," Mr Singh said while addressing district police through video conferencing here.
The DGP asked district police chiefs to issue standing orders highlighting do's and don'ts on anti-Romeo squads.
"Those caught by the squads should not be sent to jails, instead their parents should be called and their counselling be done," he said.
He said law and order is priority of the government and no one should be allowed to block roads and road discipline should be maintained.
This was the first meeting of the DGP with officers after assuming charge as state police chief.
Sulkhan Singh was appointed the Uttar Pradesh's Director General of Police in Yogi Adityanath's law and order reshuffle on Friday. He replaced S Javeed Ahmed, who was appointed to the post by the Akhilesh Yadav government last year in January.
Friday's reshuffle was the third by the 44-year-old Chief Minister who took charge of the country's most populous state last month. He had pledged not to carry out large-scale changes in the bureaucracy. But Yogi Adityanath had made it clear that officials should not expect to be undisturbed if their performance didn't quite match his expectations.