U.S. customs officers have found almost 500 fake state drivers' licenses in international cargo shipments destined for Philadelphia in operations since May, U.S. Customs and Border Protection announced Thursday.

CBP officers based in the eastern Pennsylvania city have found bogus licenses from nearly two dozen states, including Connecticut, and Nigeria.

All of the fake legal cards were shipped to the United States from China, Canada, and several countries in Southwest Asia, according to a CBP statement.

The Department of Homeland Security agency said the bust will keep the cards out of the hands of underage people who may have used them to purchase alcohol, which is illegal under the age of 21.

"Counterfeit drivers licenses have historically been used by those under 21 years of age for the illegal consumption of alcohol, but fake IDs have also been used in criminal enterprises, such as identity theft cases and immigration fraud," Casey Durst, CBP Director of the Baltimore Field Office, said in a statement.

CBP said some of the licenses were "very good quality" and even contained bar codes that could be scanned by bouncers, while others were "obvious fakes."

Some of them were turned over to state and university police investigators who will work to determine who ordered the fake cards. A portion of the licenses will be destroyed.