A professor at the University of California in Los Angeles has been suspended and placed under police protection after he rejected his non-black students' appeals for him to be lenient with his black students.

Gordon Klein, an accounting professor in the Anderson School of Business, where he has been teaching for 39 years, was suspended by the university for three weeks beginning on June 25.

The Malibu Police Department reportedly has an increased police presence outside Klein's home after multiple threats, which were made after a student, Emilia Martinez, posted an email exchange online.

A petition to have Klein removed has gained almost 20,000 signatures.

The petition seeks Klein's firing as a result of his 'extremely insensitive, dismissive, and woefully racist response to his students' request for empathy and compassion during a time of civil unrest.'

The story began when a group of students, who described themselves as 'non-black allies' of their black peers, wrote to Klein asking for him to effectively cancel the final exams for black students.