The El Mezcal Mexican restaurant in Ottawa was closed Friday because of a criminal investigation by federal immigration and customs authorities, according to a spokesman for Homeland Security Investigations, a branch of the federal agency Immigration and Customs Enforcement.

Ottawa ? The El Mezcal Mexican restaurant in Ottawa was closed Friday because of a criminal investigation by federal immigration and customs authorities.

At least three unmarked vehicles and six federal agents arrived at the restaurant about 9:30 a.m. Friday, witnesses said. The restaurant remained closed all day, the subject of an investigation by agents with Homeland Security Investigations, a branch of the federal Immigration and Customs Enforcement agency. Calls to the restaurant’s owner were not immediately returned Friday afternoon.

El Mezcal also has locations in Lawrence, which remained open Friday.

Rocky Scott, of Garnett, was one of the disappointed customers who were surprised to find the Ottawa restaurant closed Friday evening. He said he is friendly with the general manager, loves the restaurant and hopes both are OK.

“They’re fantastic people, and this is the best-run of all of them,” Scott said.

Shawn Neudauer, a spokesman for Homeland Security, said the agency could not provide details about the activity at the restaurant because it was part of an ongoing criminal investigation. But he did confirm that special agents from Homeland Security conducted the operation at the restaurant, and said the investigation also involved local law enforcement agencies in the Kansas City area and in Ottawa, including the Clay County Sheriff’s Office in Missouri, the Overland Park Police Department and the Ottawa Police Department.