TEMPE, Ariz. (AP) — Federal drug agents and Tempe police detectives have seized 30,000 fentanyl pills during an enforcement operation against a drug trafficking organization related to a Mexican cartel.

They say the pills were discovered after a traffic stop during a Drug Enforcement Administration operation last Sunday.

A search of a vehicle led to the discovery of the fentanyl-laced pills.

Authorities say the fentanyl pills were designed to look like oxycodone pills.

They were blue in color and stamped with "M'' and "30" similar to the counterfeit oxycodone pills DEA alerted the public to earlier this year.

Authorities say fentanyl is a potent synthetic opioid drug about 100 times more potent than morphine and 50 times more potent than heroin.