A security guard stands outside Dr. Walter Palmer's office in Bloomington, Minn.,as it reopens Monday, Aug. 17, 2015. The River Bluff Dental office in Bloomington had closed after a barrage of criticism for Palmer over the protected lion he killed in Zimbabwe. The office of Walter Palmer said in a tweet Monday that it will begin to see patients once again, although Palmer is not on site. (Renee Jones Schneider/Star Tribune via AP) MANDATORY CREDIT; ST. PAUL PIONEER PRESS OUT; MAGS OUT; TWIN CITIES LOCAL TELEVISION OUT

MINNEAPOLIS | The dental practice of a Minnesota man who killed a well-known lion in Zimbabwe has reopened.

Walter Palmer’s River Bluff Dental said in a tweet Monday that it was beginning to see patients again. The tweet said Palmer wasn’t at the office.

Palmer’s office in suburban Minneapolis had been closed since late July after a barrage of criticism for Palmer over the killing of a protected lion named Cecil. Palmer says he relied on his hunting guides to ensure a legal hunt in Zimbabwe.

An Associated Press reporter saw people going in and out of River Bluff Dental. A security guard posted outside the building Monday declined to answer questions and told the reporter he had to leave.

Palmer has not returned repeated calls for comment.