CINCINNATI (AP) — Officials at a Cincinnati jail say two inmates overdosed over the weekend, and its unknown how the drugs used got into the facility.

Authorities say they locked down the Hamilton County Justice Center on Saturday after the overdoses. WCPO-TV reports the two inmates were revived with naloxone and transported to the hospital.

Hamilton County Sheriff’s Office spokesman David Daugherty says jailers later found a suspicious substance on one of the inmates, resulting in the first lockdown. A second lockdown was initiated Sunday after jailers found more drugs inside the inmates’ pod.

Daugherty says officials still need to test the substances. Daugherty says jailers are still searching to determine the source of the drugs.