Kathmandu, April 28 Police arrested 16 persons with a huge amount of psychoactive substance during separate anti-drug operations in Kathmandu valley yesterday. According to Metropolitan Police Office, Atit Tamang, 24, of Sunsari district and Bikalraj Bhattarai, 36, of Rautahat district were found possessing 4,490 tablets of prescription drugs including trama, tramino and other psychoactive substances. Acting on a tip off, police raided their rented room in Sanepa, Lalitpur, leading to seizure of the drugs. Similarly, police arrested 11 suspects, including Prince Tiwari, 21, of Kathmandu with 50 tablets of trama from Satdobato, Lalitpur. In yet another anti-drug operation, the police arrested Himal Karki, 25, of Lalitpur in possession of 150 ampules of injectable drugs -- diazepam, buprenirphine and pheneragan from Kirtipur. Likewise, police held Radheshyam Chaudhary, 22, of Rupandehi district and Pushkar Budha, 19, of Rolpa district with 375 tablets of nitrazepam from Jadibuti, Kathmandu. All the arrestees have been charged under the Narcotic Drugs (Control and Punishment Act), MPO said. Police also arrested three persons with 32 ampoules of injecting drugs — diazepam, phenergan and buprenorphine from Godavari of Lalitpur yesterday. The suspects are Suman Maharjan, 25, Raju KC, 30, and Niranjan KC, 28, of Lalitpur district. Officials said they had stepped up surveillance of suspects smuggling prescription drugs into Kathmandu via Nepal-India border. Organised trade of such drugs, which can only be sold against a doctor’s prescription, is on the rise despite police crackdown. Teenagers account for the largest section of end users of pharmaceutical drugs as they are more accessible and affordable than the hard drugs. There was an alarming rise in drug smuggling in the country in the fiscal 2017-18. Statistics released by Nepal Police show that the law enforcement agency filed 3,088 cases against the traffickers in 2017-18 compared to 2,467 the previous fiscal, an increase by 22.35 per cent. According to Nepal Police, growing abuse of psychoactive substances and injectable drugs has emerged as a big problem in the country in recent days. The annual growth rate of drug users is 11.36 per cent.