NAIROBI, Kenya (AP) — Kenyan authorities issued a warning Wednesday about the sale of counterfeit HIV prevention drugs in the country, saying their “safety, quality and efficacy cannot be assured.”

The Pharmacy and Poisons Board said the drugs were in two batches falsely labeled as Truvada, a commonly used HIV prevention drug worldwide.

The board said on X, formerly Twitter, that it will take “stern legal and regulatory action” against anyone found trading, distributing, selling or dispensing from the batches.

Kenyan police fear that thousands of counterfeits of Truvada could already be in circulation on the market.

Around 1.4 million people have HIV in Kenya, according to UNAIDS data in 2022. Of those, 1.2 million are on antiretroviral therapy drugs.

Truvada is manufactured by U.S.-based Gilead Sciences Inc., which in January warned that millions of dollars’ worth of fake versions of its HIV drugs were being sold in the U.S., posing dangers to patients.

But their discovery in Kenya, East Africa’s commercial hub, shows the herculean task of tackling fake medicines.

Truvada is used in treating HIV and as a preexposure prophylaxis for people at high risk, including those with multiple sexual partners and those who share needles while injecting drugs.

Earlier this month, Kenya’s National Syndemic Diseases Control Council, a state body charged with coordinating national strategy for HIV and AIDS, raised the alarm that HIV infection rates among those ages 15 to 29 had surged by 61% between 2021 and 2022.

Across Africa, health workers have expressed concern about complacency as AIDS treatment improves.