2 people are dead and 7 others seriously ill amid fears that a batch of very high purity heroin is in circulation in Cork.
The condition of 2 of those is causing particular concern for doctors.
Ambulances have been called to 9 cases in the past 24 hours which is causing major concern for medics.
Doctors are awaiting toxicology results.
However they say it is important to issue an urgent warning immediately before anyone else is affected.
Experts are now trying to establish if the drugs involved were tainted or of very high purity.
A further update from the Health Service Executive (HSE) is expected later.
Consultant in Emergency Medicine at Cork University Hospital is Dr. Chris Luke.
He told Cork’s Red FM that all opiate users need to be on the alert.
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