Federal agents raided Oakland’s “pot university” Tuesday, as part of an ongoing investigation into the school, the Associated Press reports.

Joe Tremolada smokes marijuana as U.S. marshals raid Oaksterdam University on Monday. (Noah Berger/AP)

Local news reports suggested that the raid could be part of an ongoing federal crackdown on California’s highly profitable medical marijuana industry. (Medical marijuana was legalized in the state in 1996.)

But the Drug Enforcement Administration (DEA), which participated in the raid, told BlogPost that the raid was part of a criminal investigation into Oaksterdam University.

As agents from the Internal Revenue Service, the U.S. Marshals Service and DEA carried out the raid Tuesday, Oaksterdam students openly smoked marijuana, tried to block law enforcements vehicles, and greeted agents with shouts of “Shame!” and “DEA go away!” the Sacramento Bee reports.

Founded in November 2007 by medical marijuana activist Richard Lee, Oaksterdam is the most high-profile — if the not the only — university that teaches people how to grow marijuana.

Some call the school the “Harvard of Hemp” or “Princeton of Pot,” according to the Sacramento Bee.

The school’s stated mission is to “legitimize the business and work to change the law to make cannabis legal.” Lee explained his reasons for founding the school to the San Francisco Chronicle in 2008:

“I've seen in California that there are not enough good people who want to work in the cannabis industry in a professional way, who want to pay taxes and obey regulations and help improve their community.”

Lee said the university would operate legally.

The DEA said Monday’s raid was part of a criminal investigation into activities on the campus. San Francisco DEA spokeswoman Joycelyn Barnes told BlogPost the raid “is par for the course of what we do.” 

Barnes said Oaksterdam could stay open, depending on how it operates going forward. She would not give specifics about what activities the school would need to change.

“Marijuana continues to be a federally controlled substance, despite the fact that California voted to make medical marijuana legal,” Barnes said. “Anything involved the criminal aspects of cultivating and distributing marijuana, we will investigate that.”