In the Canadian city of Waterloo, three people were stabbed on Wednesday in a university classroom, and one person has been detained, according to police.

It was not immediately clear how many people were hurt in the attack on Hagey Hall at the University of Waterloo. The injured were taken to a medical facility.

Police reported that only one person was detained. Authorities said more information will be released as it becomes available but did not explain the attack.

A University of Waterloo student named Yusuf Kaymak told CTV News that the assault took place in a gender studies class.

“The guy basically walked in and asked the teacher if he was the professor, he said ‘yeah’ then he pulled out a knife and after that, everybody just ran out,” Kaymak said to CTV.

“I ran out, and after we went outside, there was a kid that was stabbed. He was bleeding (from) his arm. I don’t know what happened to the professor," he said.

Approximately 40 students were enrolled in the class, according to Kaymak.

Police presence will be increased, according to the authorities, "as officers continue to clear buildings and ensure public safety."

In a tweet, the University of Waterloo stated that it was assisting the police with their inquiry. There is no longer a risk to the campus community, it was stated.

Hagey Hall's Wednesday evening classes have been canceled, but all other campus activities will continue as scheduled, the university announced in a tweet.