SIOUX FALLS, S.D. (KELO) — A popular Sioux Falls restaurant is closed, and no one seems to know why.

But this isn’t the first time the Hibachi Grill and Supreme Buffet has closed its doors unexpectedly.

At the Hibachi Grill and Supreme Buffet, the doors are locked, and the sign on the entrance says “Now Hiring.” But the restaurant owners’ problems seem to go beyond finding workers.

Neighbors tell us the restaurant shut down after what appeared to be a raid.

“We noticed out back there were I think we counted eight black unmarked vehicles and somebody was getting out putting on a police vest,” said Rod Moeller, the owner and general manager at the Re-Bath Store.

Moeller business is right next door to the Hibachi Grill.

“And about an hour later we saw a couple of state patrol cars out front blocking the entrance and they all dissipated after about 4 hours,” said Moeller.

Tom Hanson: Did you see any people?

“We didn’t see anybody other than officers,” said Moeller.

Since Highway Patrol cars were out front on Tuesday we reached out to the South Dakota Attorney generals office. We were referred to Homeland Security.

The Department of Homeland Security Investigations tells us that they can’t comment on any pending or ongoing investigations. We also reached out to the Department of Labor, and the wage division tells us they do not have any ongoing investigations either.

You might remember from our reporting last year that the Department of Labor investigated wage violations at the restaurant. In that case, the Department says the owners of the Hibachi Grill failed to pay 31 workers overtime wages of more than a quarter million dollars.

We saw dozens of people walk up and try the doors over the lunch hour today. Mark Boerger from Milbank was one of them.

“Well I came down here for a doctor’s appointment and then I thought I would have lunch here and I was disappointed when the place is closed,” said Boerger.

We tried to contact the owners of H& G Inc in person and by phone but were unsuccessful. So at this point, it remains unclear how long the open sign will remain dark.