A man was rushed to the trauma centre with serious injuries following a stabbing in downtown Toronto Thursday night.

Toronto police said they were called to the area of Gerrard Street East and Yonge Street, which is near Toronto Metropolitan University, at around 8:30 p.m.

Speaking to reporters at the scene, Duty Insp. Jeff Bangild said the incident began at the northeast corner of the intersection, where two men in their early 20s had an altercation.

"It escalated to the point that one of the individuals received stab wounds," Bangild said.

The victim was rushed to a trauma centre in life-threatening condition.

Meanwhile, Bangild said officers located and arrested a suspect a short time later.

"While one person is in custody, we are still looking for evidence of that fight, the weapon that may have been used at the time, and other indicia of actually what occurred this evening," Bangild said.

He added that the suspect and victim knew each other.

"We believe it to be an isolated incident. And there's no ongoing threat to the safety of the community at this time," Bangild said.

Officers will continue to canvas the area for evidence that could help them determine what occurred. Bangild said police had already received information, including video, from several individuals.

"It is a very busy intersection …There were a number of people that were out there who may have witnessed the event," he added, appealing for witnesses who have not come forward to do so.

They are being asked to contact investigators at 416-808-5100 or Crime Stoppers anonymously.