The shooting happened in New Orleans's 7th ward, during the second-line section of a Mother's Day parade. Second-lines are a traditional part of a New Orleans parade, where parade-goers dance and follow the band on the parade route.
Police said 10 adult men, seven adult women, and both a 10-year-old boy and a 10-year-old girl were struck by bullets, with both a man and woman needing surgery because of their injuries. The 10-year-olds were in good condition, with only graze wounds from the shooting.
"Detectives are conducting interviews, retrieving any surveillance video in the area and, of course, collecting all evidence. This is an extremely unusual occurrence, and we're confident that we will make swift arrests," New Orleans Police Department spokesman Remi Braden told the Times-Picayune.
"It's sad that people can't gather together and celebrate," a 59-year-old woman said. "You don't just go into a crowd and fire into a group of innocent people."
Update: The New Orleans Police Department released video of one of the suspects.