A Hong Kong couple and their domestic worker developed symptoms of acute food poisoning two to three hours after eating wild mushrooms picked from a roadside lawn near Laguna Park in Hong Kong’s Kwun Tong district.

The three suffered abdominal pain, vomiting and diarrhea on Monday but their condition eased after they sought treatment at the United Christian Hospital.

Oriental Daily reported that the trio thought wild mushrooms could be free of pesticide and other pollutants and that boiling them in water for an extended period of time could reduce the risk of poisoning.

Media reports did not disclose more details about the trio.

The Center for Health Protection has warned to the public not to eat mushrooms other than those sold on the market, saying it’s difficult to distinguish edible mushroom species from those that should not be eaten, including some that could be fatally noxious. It said cooking could not effectively eliminate natural toxins in these mushrooms.

The center said mushroom poisoning is generally acute with symptoms appearing shortly after ingestion. Depending on the species, patients may also have other complications like profuse sweating, hallucination, coma, etc.

The center has launched an investigation into the food poisoning and will examine remnants of the mushrooms for identification.