Anthrax contaminated heroin has claimed 12 lives in Scotland so far
Health experts have warned that heroin contaminated with anthrax, which has so far claimed 14 lives across the UK, is still in circulation in Scotland.
The 39 confirmed cases of anthrax in Scotland since December 2009 have resulted in 12 deaths, seven of which have been in Greater Glasgow and Clyde.
Heath Protection Scotland said the most recent cases were over the May Day bank holiday weekend.
It said there was no way for users to tell if heroin was contaminated.
Police are investigating how this batch of heroin came to be infected with anthrax.
A Heath Protection Scotland spokeswoman said: "It is not believed it was intentional but it is more likely it was contaminated with anthrax spores at source."
There is a risk of infection from both injecting and smoking the drug.
If anthrax is contracted from an injection, the symptoms include swelling and redness at the area of the injection leading to an abscess or ulcer as well as headaches and nausea.
If contracted from smoking, users may experience nausea, breathing difficulties and flu symptoms.
Symptoms start between one and seven days after taking the contaminated heroin, and prompt action is needed if an infection is to be treated.
Heroin users are being urged to seek advice from a local drug treatment service to discuss quitting the drug or at least using safer alternatives such as methadone.