MINNEOLIS — Federal prosecutors served six grand jury subpoenas Tuesday to Minnesota officials as part of an investigation into whether they obstructed or impeded federal law enforcement during a sweeping immigration operation in Minneapolis-St. Paul area, a person familiar with the matter said. Justice Department subpoenas Walz and others in immigration enforcement obstruction probe. The subpoenas, which seek records, were sent to the offices of Gov. Tim Walz, Attorney General Keith Ellison, Minneapolis Mayor Jacob Frey, St. Paul Mayor Kaohly Her and officials in Ramsey and Hennepin counties, the person said. The person was not authorized to publicly discuss an ongoing investigation and spoke to The Associated Press on condition of anonymity. The subpoenas are related to an investigation into whether Minnesota officials obstructed federal immigration enforcement through public statements they made, two people familiar with the matter said on Friday. They said then it was focused on the potential violation of a conspiracy statute. Walz and Frey have called the probe a bullying tactic meant to threaten political opposition. Frey on Friday described the …