Federal prosecutors announced an aggressive crackdown against California pot dispensaries Friday, vowing to shut down dozens of operations and saying the worst offenders are using the cover of medical marijuana to act as storefront drug dealers.

In Maine, state officials in charge of regulating Maine’s fledgling dispensary system said Friday they are watching the reports from California carefully.

Catherine Cobb, director of the Division of Licensing and Regulatory Services at the Maine Department of Health and Human Services, noted the U.S. Drug Enforcement Agency also raided dispensaries in Montana in March.

Cobb said she is not aware if the entities licensed to operate eight dispensaries in Maine have received letters similar to ones in California, which warned dispensaries to shut down or face charges.

Five of the eight dispensaries licensed to open in Maine are operating.

“We’re kind of just in a wait-and-see mode to see where this goes,” Cobb said. “It, to me, has been a matter of which U.S. attorneys wanted to expend the resources to do enforcement in their state.”

A call to the U.S. Attorney’s Office in Portland was not returned Friday afternoon.

Augusta developer and landlord Kevin Mattson, whose company will lease space to Northeast Patients Group for a dispensary in Hallowell, said he is not concerned by what’s happening in other states.

If the federal government wanted all dispensaries shut down, they would be, he said.

“I would assume that the federal government has more important things to worry about than cancer patients getting pain relief,” he said.

Mattson said he has not received any communication from federal law enforcement.

“If I recieved anything like that, I would comply with whatever they said,” he said.

In California, law enforcement believes drug trafficking ventures are using California’s 15-year-old medical marijuana law to operate in plain sight, said U.S. Attorney Melinda Haag, the top federal law enforcement officer for the San Francisco Bay area.

“I understand there are people in California who believe marijuana stores should be allowed to exist, but I think we can all agree we don’t need marijuana stores across the street from schools and Little League fields,” she said.

Not all of the thousands of storefront pot dispensaries thought to be operating in the state are being targeted in the crackdown, which also involves new indictments and arrests of marijuana growers throughout the state over the past two weeks, said U.S. Attorney Benjamin Wager, who represents the state’s Central Valley.

Instead, federal officials are initially going after pot shops located close to schools, parks, sports fields and other places where there are a lot of children and what Wagner termed “significant commercial operations.” He said that includes farmland where marijuana is being grown.

“California’s marijuana industry supplies the nation,” he said. “And huge amounts of money are flowing back in the other direction.”

The officials declined to reveal how many dispensaries are subject to closure orders, saying only that there are dozens in each of their four districts.

The strategies they are using vary, with warning letters issued by the U.S. attorney in San Diego giving recipients 45 days to comply and 36 property owners in Los Angeles and the Central Coast given just two weeks to evict pot dispensaries or growers.

Haag said the move is not designed to clamp down on patients who grow their own marijuana for medical use. But dispensaries that were not part of the initial wave of warning letters “shouldn’t take any comfort,” she said. “They are illegal under federal law.”

The move comes a little more than two months after the Obama administration toughened its stand on medical marijuana. For two years before that, federal officials had indicated they would not move aggressively against dispensaries in compliance with laws in the 16 states where pot is legal for people with doctors’ recommendations.

The Department of Justice issued a policy memo to federal prosecutors in late June stating that marijuana dispensaries and licensed growers in states with medical marijuana laws could face prosecution for violating federal drug and money-laundering laws. The effort to shutter California dispensaries appeared to be the most far-reaching effort so far to put that guidance into action.

Kennebec Journal Staff Writer Susan McMillan contributed to this report.