Police have warned that heroin suspected of being laced with the synthetic opioid fentanyl is on the island.

It came after three people were taken to hospital for treatment of possible overdoses of the substance.

The Bermuda Police Service said an investigation into the incidents was under way.

It added: “The public are advised that fentanyl use, even in small doses, can result in serious adverse effects, which are compounded when combined with other drugs, particularly other opioids such as heroin.

“Individuals who use this drug put themselves in very real danger, which can potentially occur very soon after only one instance of fentanyl use.”

The BPS said signs of overdose included small, constricted “pinpoint pupils”, falling asleep or losing consciousness, slow, weak or no breathing, and choking or gurgling sounds.

Other indicators were a limp body, cold or clammy skin, or discoloured skin — especially in lips and nails.

Police added that the side effects of fentanyl and dangers of its misuse can include hallucinations and visual disturbances, drowsiness and nausea, confusion, respiratory distress, and rigid muscles.

Other consequences can be unconsciousness or sedation, seizures and overdose.

The BPS outlined steps to take if it is thought someone has used fentanyl or substances laced with the opioid, starting with an immediate call to 911.

It added: “Try to keep the person awake and breathing.

“Lay the person on their side to prevent choking.

“Stay with the person until emergency assistance arrives.”

• For more information on fentanyl and fentanyl overdose, visitcdc.gov/stopoverdose/fentanyl/index.html.