At least 19 people in Costa Rica have died after drinking alcohol tainted with toxic levels of methanol, local officials said Sunday.

The Costa Rica Ministry of Health said fourteen men and five women ranging in age from 32 to 72 died in June from what appeared to be methanol poisoning, local outlet the Tico Times reported. They were not immediately identified.

The Ministry of Health warned against consuming booze from a number of brands because samples had tested positive for methanol adulteration.

Affected brands include Guaro Montano, Guaro Gran Apache, Aguardiente Estrella, Aguardiente Barón Rojo, Aguardiente Timbuka and Molotov Aguardiente.

More than 30,000 bottles of alcohol suspected to be contaminated were confiscated by the government, according to CNN.

According to the World Health Organization, trace amounts of methanol are common in fermented drinks — but higher concentrations, like when methanol is added deliberately, can be deadly.

Adding methanol to distilled spirits allows sellers to increase the amount of liquid and its potential potency, according to SafeProof, a lobbying group against counterfeit alcohol.

Methanol poisoning can cause a range of side effects ranging from headaches and dizziness to seizures, coma and blindness, according to the Centers for Disease Control.