( CNN ) -- In a move that drew fire from medical marijuana advocates , federal authorities raided 26 medical marijuana dispensaries in 13 Montana cities , saying they have probable cause to believe that the businesses are involved in large-scale trafficking . The search warrants executed Monday are the culmination of an `` 18-month , multiagency investigation into the drug trafficking activities of criminal enterprises , '' Michael Cotter , U.S. attorney for the District of Montana , said in a statement Tuesday . In addition , he said , civil seizure warrants for financial institutions in Bozeman , Helena and Kalispell were executed , seeking up to $ 4 million . Authorities did not disclose items that were seized pending the filing of search warrant returns in federal court . Probable cause exists to believe that the shops were involved in conspiring to manufacture and distribute marijuana and evade financial reporting requirements , authorities said . No criminal charges have been filed . `` When criminal networks violate federal laws , those involved will be prosecuted , '' Cotter said in the statement . Individuals who are in compliance with state law are not the focus of the investigation , authorities said . Items seized included marijuana plants , computers and cell phones , CNN affiliate KULR reported . In some instances , the station said , bank accounts were frozen . Medical marijuana advocates cried foul . `` Not only are these raids very harmful and unnecessary , they are aimed at undermining the democratic process by preventing the people and legislators of Montana from addressing their own public health concerns , '' Steph Sherer , executive director of Americans for Safe Access , said in a statement . The organization describes itself on its website as `` the largest national member-based organization of patients , medical professionals , scientists and concerned citizens promoting safe and legal access to cannabis for therapeutic use and research . '' Sherer said , `` there is no doubt the raids were times to take advantage of a vulnerable political time for Montana patients . '' Shere testified last week at a state Senate hearing on a bill to repeal the state 's medical marijuana initiative . The measure , which passed the Montana House last month , died in committee , the organization said . `` The public has been hoodwinked into believing the feds have changed their policy with respect to medical marijuana , but the evidence points to the same aggressive tactics under President Obama that we saw for years under the Bush administration , '' Sherer said in the statement . Tom Daubert , who authored the 2004 medical marijuana initiative , told the Great Falls Tribune newspaper that the raids had a `` chilling effect '' on the state 's medical marijuana community . Mort Reid , the owner of one dispensary , Canni-RX in Billings , told KULR he closed his doors briefly Monday after hearing of raids elsewhere because he did n't want his patients or staff to be alarmed if he was raided . He reopened later in the day but said he is still concerned a search warrant might be executed there . Reid said he has written Montana Gov . Brian Schweitzer and said the issue is now one of states ' rights . `` We still have patients to serve and I think we as a company have to put their needs above whatever motives are behind the federal authorities , '' Reid told KULR .
Authorities allege the 26 dispensaries are involved in trafficking . Americans for Safe Access calls the raids `` harmful and unnecessary '' A measure to repeal medical marijuana in the state died in a Senate committee .