DENVER - Police are warning the public after three separate, random attacks occurred within 45 minutes in downtown Denver early New Year's Day.
Police said a total of four people were assaulted. In each incident, the victims were knocked down or knocked out by groups of black males, police said.
One victim described a blitz attack where the assailants appeared out of nowhere, striking without warning.
"It was just like that," Nick Lloyd told 7NEWS reporter Molly Hendrickson. "I didn't see anybody. I didn't hear anything. Nobody said anything to me."
Lloyd said he was waiting for a ride with a friend near 20th and Market streets when they were both punched in the face. The blow fractured his face in several places and broke his jaw on both sides.
"Basically my whole cheek is caved in," he said, pointing to his swollen and bruised face.
Denver police said it's one of three attacks that happened downtown between 1:30 a.m. and 2:15 a.m. following New Year's Eve celebrations. The assaults happened at 20th and Larimer streets, 20th and Market streets and in the 1600 block of Blake Street.
"All we have is assaults by black males, so we need more details. That's why we're asking for the community's help," said Denver Police Department Sonny Jackson.
Jackson said they're looking into whether the cases are connected. He said it could be part of an infamous phenomenon known as the "knockout game," that has happened in other cities around the nation.
YouTube videos from across the country show teenagers attacking people at random, trying to knock them out with one punch.
"It very well could be," Jackson said, when asked if the Denver attacks involved the "knockout game." "We're going to look into that. It concerns us greatly if it is." Jackson said.
For Nick Lloyd, who will undergo surgery on Friday to put plates in his face and wire his jaw shut, this is no game at all.
"I don't think it's a game, personally being on this end of it," Lloyd said. "All I can hope for is that they catch the guys that did it and you know, they get what they deserve," Lloyd said.
Police ask anyone who witnessed the attacks or who has other information about the crimes to call Crime Stoppers at 720-913-STOP (7867). Callers can remain anonymous and could be eligible for a reward of up to $2,000.