A woman has life-threatening injuries after being stabbed downtown Thursday afternoon, Toronto police say.

Police responded to reports of a stabbing in the area of King and Sherbourne streets shortly before 2 p.m.

Duty Insp. Michael Williams said two men entered an establishment in the area, and at least one of them stabbed a woman in the chest.

Toronto paramedics said the victim, a woman in her 20s, sustained critical injuries and was rushed to a trauma centre.

Police said one man was located shortly after the incident and is now in custody.

"This time, it's still very early on, and I don't have much information on their identity or their involvement in this," Williams said.

Roads in the area are closed as police investigate.

"They've actually cordoned off quite a few areas where they've located some blood trails and possibly led us to a suspect," Williams said.

He noted that several witnesses have been interviewed by police, and officers continue to canvass the area for information and surveillance footage.

Williams is urging anyone with information that can assist police in their investigation to contact them.