But instead of taking action based on past records of those detained, the main criterion behind the action was the length of their hair and their appearance.
After rounding them up from all corners of the city the police took down names, fingerprints and photos of the detainees before handing them over to their parents and guardians.
Some unlucky ones also had their hair cut by the police in presence of their guardians and were warned not sport long hair in future.
“Is it against the law that I want to keep my hair long? Are we being ruled by the Taliban,” nepalnews.com quoted an unidentified youth who was forced to cut his hair short.
The police action has sparked an online outrage with many accusing the authorities of trampling on personal liberty of residents and some demanding an apology from IGP Kuber Singh Rana.
“Who in Nepal Police comes up with idiotic ideas occasionally? What right (do they) have to arrest people for looks,” wrote senior journalist Damakant Jayshi on Twitter.
“Nepal Police has gone into retard mode if you think catching kids with long hair and earrings is going to help you catch the criminals,” wrote Tamu Hoina on Nepal Police’s Facebook page.
“Keep you tweet short or you will be thrown behind bars,” tweeted Sagar Ghimire, another journalist.
Senior police officials could not be contacted for their comments but reports in local media quoted unnamed police officials as defending the move.