A math student walked into her former instructor's office at the downtown campus of the University of Toronto and attacked him with a kitchen knife on Wednesday afternoon, police say.

Det. Jason Shankaran said the unprovoked incident unfolded at about 3 p.m. ET, inside the Earth Sciences Centre building at 22 Russell St.

The incident involving the student and the professor unfolded in an office inside the building at 22 Russell St. (Neil Herland/CBC)

"He managed to fend off the student and held her for the police to arrive," Shankaran told CBC News in an interview.

"He sustained some injuries — those injuries were cuts to his wrists, his thighs and his facial area."

The man is recovering from his non-life threatening injuries in hospital, Shankaran said.

"As you can imagine, he's pretty traumatized by the event," Shankaran said, when asked to describe the instructor's mood following the attack.

Paramedics said the victim was in his 40s. They described his injuries as minor.

Shankaran said the accused is a 21-year-old international student, who is believed to be in her second year. Police are in the midst of trying to contact her family overseas.

The university said that it is co-operating with police as they investigate the incident, which occurred just days into the start of the new school year.

More than 67,000 undergraduate students and nearly 16,000 graduate students attend the University of Toronto, according to statistics posted on the school's website.