A protest in Minnesota (File photo)

A US federal judge on Saturday refused to pause a stepped-up immigration enforcement operation in Minnesota, even as a lawsuit challenging the move continues. The ruling allows the federal action, known as Operation Metro Surge, to carry on in Minneapolis, St Paul and surrounding areas.US District Judge Katherine Menendez denied a request for a preliminary injunction filed by Minnesota Attorney General Keith Ellison and the mayors of Minneapolis and St Paul. They argue that the Department of Homeland Security is violating constitutional protections and overstepping federal authority.In her ruling, Menendez said both sides had presented evidence and that it was not yet clear whether the state’s legal challenge would ultimately succeed. “The Court is reluctant to find that the likelihood-of-success factor weighs sufficiently in favour of granting a preliminary injunction,” she wrote.Federal lawyers have defended the operation, saying it is aimed at removing criminal immigrants and has been made necessary by state and local sanctuary policies.While refusing to halt the operation, the judge noted serious concerns about its impact. She said there was evidence of a “profound and even heartbreaking” effect on communities, including claims of racial profiling and excessive force by federal agents.