BANGOR, Maine — A Mexican national faces a charge of illegally entering the United States after federal agents raided the Twin Super Buffet in Brewer on Wednesday.

Walter Cruz Sanchez-Armira, a 24-year-old Mexican citizen, was questioned and arrested after Department of Homeland Security investigators determined during an interview at the Chinese restaurant that Sanchez-Armira hadn’t obtained proper documentation to enter the United States, according to an affidavit filed in U.S. District Court.

Local police and federal agents raided Chinese buffet restaurants in Brewer, Lewiston, Waterville and the Portland area on Wednesday — reportedly operated by members of the family-run “Zhang Operation” — shutting at least four of them down temporarily.

Zi Qian Zhang reportedly is the leader of the Zhang Operation along with his wife, Ai Hui Lu, both of Massachusetts, according to a federal complaint.

Brewer police and federal agents raided the Twin Super Buffet in the Twin City Plaza, a “safe house” on Elm Street and a second residence on Wilson Street that is owned by a member of the Zhang family.

Sanchez-Armira told agents that he had been deported from the United States in March 2008, which was confirmed when investigators sent his fingerprints through a database.

According to the affidavit, Sanchez-Armira crossed the border from Mexico into Arizona by walking through the desert just seven or eight months after his deportation.

Sanchez-Armira is charged with illegal entry into the United States after having been removed or deported, a Class E felony that carries a penalty of up to two years in prison and a fine of up to $250,000.