Police were called to Queen Street West and Dowling Avenue just before 1:30 a.m. where they found a man and a woman with stab wounds. Both were taken to hospital with serious injuries.
Approximately an hour later and about two blocks away, police arrested two men suffering from slash wounds. Both are expected to recover.
Staff Sgt. Niels Sondergaard said they believe the incident started with a fight outside a local bar.
It's not clear whether charges will also be laid against the man and the woman.