Demonstrators at the vigil in Yonge Dundas Square prayed for the dead — Deah Barakat, 23, Yusor Abu-Salha, 21, and 19-year-old Razan Abu-Salha — who were shot to death in Chapel Hill, N.C. on Tuesday.
The shooting is said to have sprung from a parking dispute. But police are looking into whether the alleged killer was motivated by hatred toward the victims because they were Muslim.
The crime has already sparked fear among many Muslims.
"Whether it be in Chapel Hill or here in Toronto — we need to talk about what the cause is of Islamophobia. Nobody is born Islamophobic," said vigil organizer Riaz Sayani-Mulji.
Some attendees said they have little doubt the killings were motivated by hate.
"I don't think any person would kill three Muslim students and shoot a bullet in their head over a parking dispute," said demonstrator Maaz Khan.
U.S. President Barack Obama condemned the killings on Friday, saying no one should be a target because of their appearance or how they worship.