Minneapolis’ police chief is criticizing federal immigration agents after a confrontation with protesters and an attempted arrest of a woman in which an officer kneeled on her back as she lay atop a snow bank and then tried to drag her to a car.

Tensions have been rising in the Minneapolis-St. Paul area as federal authorities continue an immigration crackdown focused on the region’s Somali community, the largest in the country.

Onlooker video of the confrontation showed people yelling at Immigration and Customs Enforcement agents to release the woman, claiming she is pregnant and couldn’t breathe. After kneeling on her, an agent later dragged the woman by one arm on her back toward a vehicle.

“Let her go! Let her go!” onlookers yelled as the agent dragged the woman at an intersection close to a Somali business district. The woman was eventually let go.

Police Chief Brian O’Hara told a news conference that city police were called to the confrontation by a federal agent who said officers needed help. When police arrived, they did not see violence against federal officers and left in an effort to de-escalate the situation. He added that other law enforcement agencies may have been using questionable methods.

“We have been training our officers for the last five years very, very intensely on de-escalation,” O’Hara said. “But unfortunately that is often not what we are seeing from other agencies in the city.”

Department of Homeland Security assistant secretary Tricia McLaughlin stated that federal officers were targeting a vehicle when protesters allegedly threw rocks and assaulted officers. The officers sustained multiple injuries, including cuts, and two individuals were charged with assaulting federal officers.

Officers attempted to arrest the woman shown in the video because she reportedly rushed an ICE vehicle and attempted to vandalize it, but the arrest was abandoned after they were swarmed by protesters.

Hodan Hassan, a former Minnesota state legislator, expressed concern that ICE tactics appear to be becoming more aggressive as the Minneapolis-St. Paul operation continues, noting a marked increase in aggression within the operations over the weeks.