The Food Safety Authority of Ireland has warned people of the dangers of consuming wild shellfish gathered on the west and southwest coasts.
The FSAI said it had received reports of more than ten people in Galway, Sligo and Mayo becoming ill with suspected cases of shellfish poisoning.
It is believed the illnesses are linked to harmful algal blooms occurring along the west and southwest coasts.
FSAI Chief Executive Alan Reilly said some residents and visitors gathering shellfish in the region may be unaware of the dangers of consuming the shellfish.
Professor Reilly said: "Wild shellfish found along the west coast may contain naturally occurring toxins that cannot be removed through cooking alone.
“Eating shellfish contaminated with these toxins can lead to people suffering nausea, vomiting, diarrhoea, and stomach cramps."
“The effects are not life-threatening but can be particularly severe for older people, young children and people who may already be ill from another medical condition," he added.