The Toronto van attack that devastated the city on Monday afternoon leaving 10 people dead and 15 others fighting for their lives in hospital was “definitely deliberate” Toronto police said.

Toronto police confirmed the 25 victims while speaking to reporters approximately three hours after the incident.

The incident occurred in North York in the area of Yonge Street and Finch Avenue shortly before 1:30pm on Monday. The area remains closed to the public to accommodate the large-scale investigation.

"We're all putting our pieces together to see exactly what we have," Toronto police Chief Mark Saunders said to reporters.

Saunders said the attack "definitely appeared deliberate," but what motivated it was less clear. He also told reporters that the majority of victims had not yet been identified.

Alek Minassian, 25, was arrested shortly after the horrific attack. Minassian appeared in court wearing a white jumpsuit on Tuesday morning, where he was charged with 10 counts of 1st-degree murder and 13 counts of attempted murder.

Part of the investigation will involve trying to understand what prompted someone to turn a rental van into a weapon.

When asked if the city is safe, Saunders said: "Yes, the city is safe."

Anyone with any information regarding this investigation is asked to call officers at 416-808-8750 or submit footage to a website that has been set up by police.