Authorities are sounding the alert for Americans traveling to Mexico, warning that methamphetamine had been found in bottles of 7-Up. According to a news release from nonprofit Banner Health, bottles of 7-Up had been discovered with the drug in them, and had been consumed in Mexicali, Mexico.

Authorities are investigating how this happened. It resulted in the death of one person and seven other people falling ill. Officials have removed the contaminated soda from shelves. Mexicali is situated on the border between California and Mexico border, about two hours drive from San Diego.

The issue does not appear to affect 7-Up products sold in the United States. Dr. Pepper Snappel Group said the company doesn’t market or sell the brand in other parts of the world.

“Medical Toxicologists and Emergency Department physicians are on high alert after reports of tampering to soft drinks emerged from Mexico several days ago,” reads the statement from Banner Health. “These reports indicate that 7UP bottles consumed in Mexicali, Mexico, were contaminated with methamphetamine. An investigation is underway to determine how the drinks were contaminated.”