Officials from Nigeria’s National Agency for Food and Drug Administration (NAFDAC) are asking a number of pharmacies that were recently found to be selling counterfeit drugs to reveal the source of the fake medication.

A special NAFDAC team from Lagos found 20 pharmaceutical and medicine shops in Yola, the capital of the Adamawa State, dealing counterfeit drugs through on-the-spot screenings, according to the Nigerian Observer. The operations leader and team leader of NAFDAC’s head of the Ports Inspection Directorate Momodu Segiru said that the agency is appealing to the pharmacy owners to provide information on the counterfeit drugs “so that we can trace the source for necessary action.”

Segiru told the news source that finding counterfeit drugs were typical throughout the country.

“We went to many states and found that the same type of drugs, that is antibiotics and antimalaria, are the ones being speculated,” he said.