Toronto police are on the hunt for one or more people who opened fire on two people as they left a party in Regent Park, killing them both.

Police said that Jermaine Derby, 19, and Sealand White, 15, were leaving a party they were attending in an apartment building at 605 Whiteside Place, off Dundas Street East near River Street, at around 2 a.m on Saturday.

The two were exiting the elevator into the lobby when one or more suspects opened fire, who then fled the scene.

Investigators said one of the victims made his way through the front entrance before collapsing in the front driveway. The second man took the elevator to the building's sixth floor, where he collapsed.

Emergency crews attempted to save the victims. One person died while being treated in the back of an ambulance; the other died later in hospital.

Toronto police were on the scene Saturday and continue their investigation. Detectives are reviewing security cameras at the building.