A large federal law enforcement presence in South Minneapolis drew protests Tuesday.

Officials from the FBI, ATF and the Department of Homeland Security gathered with tactical vehicles at the corner of Lake Street and Bloomington Avenue late that morning.

The Hennepin County Sheriff’s Office, in a statement posted online, said the operation was for the execution of a search warrant as part of a criminal investigation.

“The incident was not related to any immigration enforcement,” the sheriff’s office reported. It said its deputies partnered with federal agencies to execute “multiple search warrants at multiple locations in the metro area.”

Minneapolis Mayor Jacob Frey posted a statement saying that the incident “was related to a criminal search warrant for drugs and money laundering and was not related to immigration enforcement.” Frey said no one was arrested.

While Minneapolis police were at the scene once the operation started, Frey said their presence was only for crowd control.

The FBI told MPR News that the agency was “conducting court-authorized law enforcement activity,” and that it did not have any other information to share.

But the incident happened amid heightened concerns over federal immigration enforcement actions in Minnesota and across the country — concerns that prompted protesters to gather in the area.

Some attempted to block law enforcement vehicles from leaving the area on Lake Street. MPR News journalists at the scene witnessed protesters throw tires and other items in front of departing vehicles.

At least one law enforcement officer appeared to deploy a chemical irritant in response.

There were no immediate details on any injuries in connection with Tuesday’s law enforcement action or subsequent protests.

Minneapolis Police Chief Brian O’Hara was seen walking with federal agents at the scene.

Minneapolis police said they were not given any advance notice of a federal operation in the city; the department said it responded to the area once the operation was underway, and after the crowd had gathered.

In a statement issued later Tuesday, Unidos MN, a social justice group, said many questions remained about the incident.

“There is much that we need to learn from this situation, and we wait for our elected officials and law enforcement to explain what happened in our community today. … These types of highly militarized operations involving federal agencies, without any information provided to the community, strikes fear and reduces the ability of the community to have confidence that law enforcement is there for protecting the community.”