Witnesses say they saw one man jump from a seventh floor balcony in an apartment building between Bidwell and Denman streets in the Downtown West End around 3:30 p.m. PT.
The man apparently fell to the third floor and was later taken to hospital with minor injuries.
Witnesses said a second man limped bloodied into the nearby Boathouse restaurant and claimed to be the target of a robbery.
"My hostess grabbed me and said someone is bleeding. I came out and thought it was an altercation," said restaurant manager Darrick Wan.
"He was on the phone calling police. We helped him out, patched him up and all of sudden police started showing up."
Armed with machine guns and battering rams, Vancouver police officers swept the apartment and its rooftop.
Two other uninjured victims, a man and woman, were found by police inside the building, but police say the suspect had already fled.
Police say both of the injured men were known to police and they believe the incident was some sort of targeted attack.
Monica Wilson, another nearby renter, often leaves her balcony door unlocked. Now, she says, "I'm thinking maybe I should be more careful."