The Minnesota dentist who killed Cecil the lion in Zimbabwe has returned to his clinic after weeks out of the public eye.

Walter Palmer entered his Bloomington clinic at about 7am without speaking to members of the media gathered outside.

He parked nearby and walked to his clinic from the street. A staff member met him on the street, grabbed his arm and parted a throng of journalists to rush him to the front door.

Employees have also been escorting patients from their vehicles into Mr Palmer's clinic.

Bloomington police are trying to minimise traffic congestion and no problems have been reported so far.

In an interview with The Associated Press and the Minneapolis Star Tribune, Mr Palmer reiterated that his hunt was legal.

Cathy Pierce, who was wearing a shirt with Cecil's photo, shouted "extradite Palmer" as the dentist was whisked inside the clinic.

Zimbabwe has not sought to extradite Mr Palmer, who said it is unfair that protesters are targeting his family and staff.

Ms Pierce said she is only targeting Mr Palmer, who she says should face punishment in Zimbabwe.

A woman who lives near the clinic said people should leave Mr Palmer alone.

Stephanie Michaelis argued with the protesters. She said the uproar about Cecil's death is unfounded and that people should be more concerned about abortions and threats to human life.

She called the protesters "crazies".