MILWAUKEE -- Twenty-one people were injured in three separate shootings in downtown Milwaukee near an entertainment district where thousands had been watching the Bucks lose to the Boston Celtics in Game 6 of the NBA Eastern Conference semifinals, authorities said. Three people were shot near the Deer District outside Fiserv Forum toward the end of Friday night's game, sending fans fleeing through the streets. One person was injured in a second shooting before a third shooting less than a mile from the arena left 17 people with non-life-threatening injuries, police said. A man and a 16-year-old girl who were injured in the first shooting were transported to a local hospital Friday night, while a third person drove there, according to the Milwaukee Fire Department. All three have non-life-threatening injuries. Police said a 19-year-old man was in custody from the first shooting and that charges were pending a review by the Milwaukee County district attorney's office. No arrest has been made in the second shooting, Assistant Police Chief Nicole Waldner said. Ten people were taken into custody and nine firearms were recovered from the third shooting, according to police, which described the incident as an exchange of gunfire between two groups of people. "What makes people think they can just have a shootout on a public street or in an entertainment district, whether police are there or not?" Waldner said at a noon news conference. Five of the injured in the third shooting were armed and among the 10 people taken into custody, Waldner said. Milwaukee Mayor Cavalier Johnson said the city imposed a curfew for the downtown area requiring everyone age 20 or younger to be off the street by 11 p.m. for Saturday and Sunday. Extra police patrols also are planned. "We cannot have that in this city, nor anywhere else in this state, nor anywhere else in this country," Johnson said. The Bucks canceled Sunday afternoon's watch party in the Deer District for Game 7, which will take place in Boston, to allow law enforcement to devote needed resources to their continued investigation. "The shootings that happened in downtown Milwaukee last night were horrific and we condemn this devastating violence," the Bucks said in a statement. "We are grateful to local law enforcement for its valiant efforts to try to contain what was a dangerous and fluid situation. "While these incidents took place outside of Deer District property, it clearly resonated with fans coming out of the arena and leaving the plaza." Milwaukee Police have not said whether the shootings were connected, and investigations are ongoing. "The incident took place outside of the Deer District area," Bucks chief communications officer Barry Baum said of the first shooting in a statement to ESPN. "We direct all questions to the Milwaukee Police Department." Bucks fans began packing into the Deer District during the team's run to the NBA championship last season. With a chance to clinch the Eastern Conference semifinal series against the Celtics and on a warm day following a long winter, Friday was the first opportunity for fans to pick up the tradition. The team had set up metal detectors surrounding the bars and entrance to the stage outside the arena. The first shooting took place outside that perimeter, about one block from Fiserv Forum. The Bucks announced before the game that the Deer District had reached the 11,000-person capacity set for the watch party before Game 6. Witnesses outside the arena said they heard gunshots with a little more than a minute remaining in the fourth quarter of Boston's 108-95 victory that tied the series 3-3, and those shots sent many in the crowd into a frenzy, running in several directions. A large police presence remained outside the arena hours after the game, with police taping off several intersections nearby. The Associated Press contributed to this report..