The Health Service Executive has confirmed that a second batch of illegal drugs linked to overdoses in the Dublin region was identified as heroin adulterated with nitazene drugs.
Nitazenes are strong synthetic opioids and are deemed as having a substantial risk due to their high potency.
Over the last 24 hours, the HSE said, it had been informed of an additional eight ambulance callouts associated with drug overdoses.
This brings the total number of reported overdoses since last Thursday to 54.
In a statement, the HSE said it remains "very concerned about a new batch of brown powder circulating in the Dublin city centre region."
It said that "it is safer not to use drugs at all" but reminded people to be extra careful, avoid using new drugs, new batches of drugs or buying from new sources.
Last week, Dublin City Council posted an urgent HSE message on screens around the city with an overdose warning.
Contact the HSE Drug and Alcohol Helpline on 1800 459 459.
