Employees working in the building described the chaos as emergency crews rushed to the scene of a stabbing at a Yonge Street office building.

"Guys were running in fairly quickly with their shotguns out, so it was pretty serious," Steve Courier, an employee in the building, told CTV Toronto.

"I just saw two people being escorted to an ambulance. One had bandages around his head and the other had a torn T-shirt. There are a lot of police and EMS people moving around, but outside it is not much of a scene," Tony Bitonti, who works in the building next door, told CP24.

"I got some texts about what happened so I came outside, saw some people with blood on them and now there are trucks and paramedics all around," Razvan Nicolae, who also works next door, added.

Police say Chuang "Ray" Li, 47, from Mississauga, Ont., is facing three counts of attempted murder, four counts of aggravated assault, and four counts of assault with a weapon.

Officers were called to the Yonge Street offices of Ceridian Canada just after 9:30 Wednesday morning, after reports of a man attacking his co-workers with a sharp implement.

Li was escorted out of the building by police soon after the incident and was seen with his hands covered in what looked to be blood.