Police say people are experiencing significant side effects from the tablets
Police in a south Wales community are trying to tackle the supply of valium after a number of people, including children, have been taken to hospital.
Neath Port Talbot officers say people who have taken them have suffered a number of adverse side effects.
Four people have been arrested on the Sandfields estate in Port Talbot, and police say suppliers are targeting children with the blue tablets.
They said youngsters from "mid teens upwards" were being approached.
Valium tablets and other drugs were recovered during Friday's operation.
Det Insp Dave Wright of the Neath Port Talbot Police pro-active team said: "We are concerned about the impact this valium is having on the behaviour of individuals, especially youngsters in the Sandfields area where the problem seems to be more prevalent.
"Our intelligence suggests the supply of valium is plentiful at the moment and our work will be concentrating on targeting those who are supplying the tablets."
The arrests were made on Friday after search warrants were executed at a number of addresses in the Sandfields area.
"We are aware that the suppliers have been targeting school children and because the origin and make-up of the valium is not known, those who are taking it are putting themselves at risk of serious ill health or even death," said Det Insp Wright.
"We are seeing people, especially youngsters, coming into custody displaying serious side effects and requiring hospital treatment. After taking these tablets the young people cannot remember where they have been or what they have done from one day to the next."
Samantha Michael, a drugs worker with the West Glamorgan Council on Alcohol and Drug Abuse, based in Port Talbot, said valium abuse was quite common among clients.
"The effects maybe similar to alcohol," she said.
"It's a drug that commonly used as a secondary drug by people using alcohol, heroin or even cocaine.
"One of the main concerns is it is extremely addictive but withdrawal can be prolonged and extremely painful."
She said as it was now prescribed less frequently by GPs then some people had taken to buying it on the internet, which meant they could not be sure what they were taking.
Det Insp Wright added: "I would ask parents to look out for any unusual or incoherent behaviour and to contact the police should they have any concerns.
"The police are working with partners to spread the message that these tablets are a serious health risk. I would urge anyone offered or in possession of a suspected blue valium tablet not to take it, but destroy it or hand it into the police."
Anyone with information is asked to contact police at Neath Port Talbot on 01792 456999 or Crimestoppers on 0800 555 111.