Students in Holyhead have been warned about the dangers of taking ketamine as part of a pilot scheme.
North Wales Police teamed up with emergency services and health organisations for 'Be Smart, Don't Start' - a two-day event held in response to growing use of the drug in recent years.
It comes after a panel of UK Government experts decided against reclassifying ketamine from a Class B to a Class A drug.
Over 250 pupils from Holyhead High School took part in interactive workshops and open coversations about the potential risks.
Chief Inspector Jon Aspinall said: "We are working with partners continuously to stop the harm that drugs cause in all parts of our communities."
"Recent action has resulted in two individuals being arrested on suspicion of possession with intent to supply ketamine. Another way we are tackling the rising concerns around ketamine is through prevention and awareness."
"The event this week reinforced the importance of making positive choices, staying safe and looking out for others."
Among those taking part in the event were Be Di'r Sgor? (What's the Score?), which provides advice to young people across Anglesey and Gwynedd about substance misuse.

School police officers spoke about the laws surrounding drugs and the potential impact of a criminal record, while nurses told students about the long-term health impacts, such as the link to bladder problems, which could result in needing serious surgery and using stoma bags for life.
Sharon Thomas, a stoma nurse from the Betsi Cadwaladr University Health Board, said: "I really enjoyed attending and speaking to the young people. It was important to have open and honest conversations about the dangers of ketamine and the very real consequences it can have."
"If sharing this information helps even one young person stop and think before taking something that could change their life forever, then it’s absolutely worth it."
Pupils were also given advice on support services available to young people, as well as early intervention and confidential reporting.

Stella Dennis-Bunting, deputy head at Holyhead High, said: "We are committed to ensuring our pupils are informed, safe and supported."
"Hosting the ‘Be Smart, Don’t Start’ event gave our students the opportunity to learn about the real dangers of ketamine in an open and engaging way. We are grateful to all partners who helped deliver such an important message and provide clear pathways to support."
Also taking part in the event were dental nurses, the Ynys Môn Youth Service, the Welsh Ambulance Service Trust and CAMHS (Child and Adolescence Mental Health Services)
CI Aspinall added: "Using ketamine can seriously harm your health and people who are considering taking it, especially young people and teenagers, may use it without understanding the consequences."
"We will continue to act on intelligence against those involved in the supply of ketamine and will robustly pursue and bring individuals to justice to stop young people from being targeted."
Anyone with information about drug crime on Anglesey can contact North Wales Police on 101 or via the live web chat or Crimestoppers anonymously on 0800 555 111.
If you'd like to talk to someone about any drug problems, call DAN 24/7 on 0808 808 2234 anytime 24 hours a day.


Inquest opens into walkers' deaths
More funding for Holyhead regeneration projects
Wylfa: ministers pledge to maximise SMR benefits
Exclusion zone reintroduced at The Range
Energy funding for sports clubs