Federal agents from the U.S. Marshals Service, the DEA and the IRS descended on Oaksterdam University sometime after 7 a.m. this morning, effectively shutting down the cannabis industry trade school school while carrying out a federal search warrant. Because all the paperwork for the raid is still under seal, an IRS spokeswoman on the scene could not disclose the reasons for the sudden closure other than to confirm that it is part of an ongoing joint investigation. NBC Bay Area reports that the school at 16th and Broadway, the nearby Oaksterdam gift shop and the Oakland Cannabis Buyers Cooperative were all among the four locations shut down by the feds this morning.

The raid in Oakland comes after federal agencies have been issuing warnings and shutting down local dispensaries for operating too close to schools or parks. Two weeks ago, on March 14th, Oakland officials voted to double the number of cannabis dispensaries in the city.

We'll continue to update as we know more.

Update: KTVU has additional reports from the scene where agents were seen carting trash bags filled with plants out of the building and in to a large truck outside. Richard Lee, the school's owner, was reportedly detained in the raid, but other sources on the scene are now claiming he has been released. Meanwhile, small crowd of demonstrators assembled outside the school, calling for an end to the federal crackdown on medical marijuana:

KTVU2 has also posted a video report from the scene this morning. Federal authorities told press outside Oaksterdam that there will be a press conference sometime this afternoon to shed some more light on the raid.

Previously: all Medical Marijuana coverage on SFist