Three masked robbers struck a McDonald's in Plymouth early Wednesday, forcing employees into the freezer and then getting the money to go, authorities said.

No one was hurt in the holdup shortly before 3:30 a.m. at the 24-hour fast-food outlet near Interstate 494 and Hwy. 55, according to police. There were no customers there at the time when the four employees told officers that three suspects, all males and one with a black semi-automatic handgun, entered the building, police said. While some workers were corralled into the freezer for about 10 minutes, the manager turned over thousands of dollars in cash, though police declined to disclose the full amount.

Police Capt. Jeff Swiatkiewicz said investigators have reviewed surveillance videos, but the men were in the building for no more than five minutes and had their faces concealed, wearing black and red hoodies and white gloves. .

About a year ago, a Burger King in Plymouth was robbed by an employee. Swiatkiewicz said investigators haven't ruled out former employees' involvement with the McDonald's robbery. Anyone with information is asked to call police at 763-509-5160.