Mexican authorities have seized a large amount of the powerful synthetic opioid fentanyl along with other drugs hidden in a car near the U.S. border.

The National Security Commission says the vehicle was searched on a highway between the Gulf of California and San Luis Rio Colorado, which is home to a border crossing with southwest Arizona.

A statement Monday says the bust included 31 pounds (14 kilograms) of fentanyl, which can be fatal in doses of just a few milligrams.

By comparison a seizure last month of 4.5 pounds (2 kilograms) of fentanyl in Columbus, Ohio, was said by prosecutors to be enough to kill the entire population of the city of 860,000 people.

Meth, cocaine and heroin were also seized from the car. Three people were detained.