All of the victims are black, sparking concerns that the shootings were racially motivated.
"We're not absolutely certain, but a hate crime is a possibility," Tulsa police spokesman Capt. Jonathan Brooks told CNN. "This is not your standard homicide."
All five people were shot within seven hours.The shootings also occurred within the same area of North Tulsa, a local Fox station reported.
North Tulsa is a predominantly black area, and local residents are now fearing for their safety.
"We're all nervous," North Tulsa resident Renaldo Works told the AP. "I've got a 15-year-old, and I'm not going to let him out late. People are scared. We need facts."
The news comes as racial tensions continue to flare over last month's shooting death of black teenager Trayvon Martin. His shooter, George Zimmerman, has not been arrested. A Gallup/USA Today poll released Thursday found that 73 percent of black people believe Zimmerman would have been arrested if Martin was white. Just 33 percent of whites agreed.