Protesters and ICE agents clash as an officer arrests and drags a woman by her arm at West 29th Street and Pillsbury Avenue in south Minneapolis on Monday.

The Minneapolis police chief is among those criticizing U.S. Immigration and Customs Enforcement (ICE) after video shared by a local reporter shows federal agents kneeling on a face-down pregnant woman in hardened snow before dragging her by one arm along the street.

The ACLU filed a lawsuit against ICE for violating the constitutional rights of Minnesotans observing enforcement activity and for arresting U.S. citizens.

The lawsuit says ICE agents pepper-sprayed, arrested and “even followed observers home to scare them in a tactic lifted straight from the mafia.”

Minneapolis Police Chief Brian O'Hara expressed concerns about the “instability" created by the ongoing ICE operation in Twin Cities, especially confusion caused when federal agents aren't clearly identified.

The Department of Homeland Security’s Minnesota-focused enforcement campaign has been underway for several weeks, and the agency says it’s resulted in more than 400 arrests so far. The Minnesota effort,