Two medical marijuana providers have accused the U.S. government of civil rights violations in what may be the first lawsuit of its kind in response to a federal crackdown on pot operations across the nation.

The owners of Montana Caregivers Association and MCM Caregivers claim federal raids on pot businesses across Montana in March were unconstitutional, exceeded the government's authority and pre-empted the state's medical marijuana law.

Since then, federal agents have raided two Washington state dispensaries, and federal prosecutors have sent letters of warning to leaders in most of the 15 states with medical marijuana laws.

The lawsuit was filed Tuesday in U.S. District Court in Missoula against the government, Department of Justice, Attorney General Eric Holder and U.S. Attorney for Montana Michael Cotter.

The plaintiffs claim the intent of the raids was to shut down the medical pot industry.

"The federal government has made clear its intent to threaten and eventually eliminate any business or enterprise related to the medical use of marijuana," Christopher Williams of the Montana Caregivers Association and Randy Leibenguth of MCM Caregivers claimed in the lawsuit.

The Department of Justice did not comment when contacted Wednesday. Cotter spokeswoman Jessica Fehr also declined comment, saying the U.S. attorney's office had not been served with the lawsuit.