BERKELEY -- The federal government filed a lawsuit targeting the city's largest medical marijuana outlet and is aiming to seize the property from its landlord.

The suit, filed May 2 in U.S. District Court in San Francisco, says Nahla Droubi of Moraga, who is the landlord for Berkeley Patients Group, is breaking federal drug laws by allowing the sale of marijuana and therefore is subject to seizure of her property.

The suit comes after Berkeley Patients Group was forced to close its previous location down the street on San Pablo Avenue last May when the landlord there received a letter threatening seizure for the same reason. The letter also cited the fact that it was too close to two nearby schools.

It then moved down the street and reopened in December.

Sean Luse, chief operations officer for Berkeley Patients Group, which has been doing business in the city since 1999, said he was surprised at the suit because he did everything asked of him when he was forced to leave the last location.

"We moved our previous location and moved 1,000 feet from any school, so we're very surprised," Luse said.

The lawsuit against the Berkeley Patients Group landlord, in addition to citing federal drug laws, also mentions the proximity of two preschools in the neighborhood near the new location.

Luse said Berkeley Patients Group will join the lawsuit as a defendant and stay in business as the saga unfolds.

"We look forward to our day in court," he said.

Last August, Droubi said she was not worried about having her property seized when Berkeley Patients Group announced it would become her new tenant.

"Our property is not close to any school," she said at the time. "The previous landlord had a very good experience with this group. He said they were very organized and most important thing is they had no violations and great security."

Droubi did not respond to calls seeking comment Tuesday afternoon, nor did a spokesman for the U. S. attorney in San Francisco.

The lawsuit is similar to one filed last year against Harborside Health Center in Oakland, the nation's largest medical marijuana dispensary. That lawsuit has not yet been resolved.

Kris Hermes, spokesman for Americans for Safe Access which advocates for medical marijuana with 50,000 members nationwide, said there have been about 20 dispensaries targeted in a similar fashion across California in the last couple of years, but he did not know how many of the suits have been successful.

He said the U.S. attorney's office has sent hundreds of letters to landlords threatening forfeiture "and hundreds have shut down as a result."

More recently he said a new round of threatening letters has recently gone to landlords of dispensaries in San Francisco and San Jose.

"The Obama Administration has so far gotten away with claiming that they are only targeting those in violation of state law," Hermes said. "Berkeley Patients Group stands in direct contrast to that contention. It's patently false."

Four Berkeley City Council members plan a news conference on Wednesday at noon, at 2134 Martin Luther King Jr. Way, to protest the lawsuit.

Doug Oakley covers Berkeley. Contact him at 510-843-1408. Follow him at Twitter.com/douglasoakley.