The shooting happened around 1:45am not far from police headquarters in Lawrence, in an area crowded with people from concerts, bars and events at the nearby University of Kansas, which was celebrating the start of college basketball season, AP reported.
Officers heard more than 20 gunshots, Interim Police Chief Anthony Brixius said. Brixius said responding officers found several people wounded in a large crowd.
Police didn't say what led to the shooting, and no arrests had been made as of Sunday afternoon.
The victims who died were identified as 22-year-old Leah Elizabeth Brown of Shawnee, and Topeka residents Colwin Lynn Henderson, 20, and Dupree Dean, 24. None was a student at the school, according to university spokeswoman Erinn Barcomb-Peterson.
Brown's mother, Gretchen Brown, said her daughter's friend told her the two had just left Brothers Bar & Grill before the shooting. When the women reached the street, Brown said they saw a fistfight nearby. Then gunfire rang out, and Leah Brown collapsed.
The names of the wounded victims weren't immediately released. They were being treated for injuries not believed to be life-threatening, according to police.
Lawrence resident Kyeeton Soukup told the Lawrence Journal-World he was inside Pyramid Pizza when someone came in and shouted, "Oh my God, there has been a shooting outside!" Soukup said he ran outside and saw two shooting victims on the sidewalk. He said paramedics arrived shortly after.