At least 48 people have died and 182 others fallen ill after consuming locally prepared alcoholic and herbal concoctions in Nigeria’s Ondo State.

The country’s food and drug regulator, NAFDAC, said laboratory tests found high concentrations of methanol in samples of the suspected drink. The toxic substance can cause blindness, organ failure and death.

Authorities said five people have been completely blinded, while two others suffered partial loss of sight. Fifteen people have been arrested over the production and sale of the drink.