(CNN) -- A man walked in and opened fire at a Hmong New Year's celebration in Tulsa, Oklahoma, on Saturday night, injuring five people, police said.
Authorities don't know what caused the man to begin shooting inside the Green Country Event Center. He has been arrested.
Two attendees were hit in the upper body, while the other three were struck in the arm and leg, said Tulsa Police Capt. Mike Williams.
They were between the ages of 30 and 60.
"One of the individuals will probably lose his lower leg," Williams said.
A police helicopter that happened to be flying by saw a vehicle leaving the area. When officers tried to stop the car, they saw a passenger changing clothes, then throwing his hoodie and a gun from the car, Williams said.
Police believe the passenger, 19-year-old Ming Mee, was the shooter.
Both he and the driver, 21-year-old Boon Mee, were arrested.
The Hmongs are an Asian ethnic group. There are an estimated 210,000 Hmongs scattered across the United States.
They were an important U.S. ally during the Vietnam War. Many fled the Communist government when combat ended.