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.

Tim Walz, Jacob Frey, Kahly Her, Keith Ellison and Mary Moriarty were issued subpoenas by the federal government.

Federal prosecutors have served six grand jury subpoenas to Minnesota officials as part of an investigation into whether they obstructed or impeded federal law enforcement during…