A teenager has been seriously injured in a stabbing incident inside the Yorkdale shopping center in Toronto, Canada. Four suspects are believed to be on the loose, possibly “still in the mall.”

The teenager, whose injuries are described as “very serious,” was stabbed on Monday evening at the entrance to the cinema inside the busy mall. Police are searching for four suspects, at least two of whom have been described as black males. Another man and woman are believed to have been involved in the incident, the police official said.

“There are several units on the scene searching in and around the entire area. It is unknown if the suspects are still in the mall,” Toronto police spokesperson Allyson Douglas-Cook said.