Eight people were killed and six others injured when a man entered a nightclub in the Colombian city of Cali and opened fire, police said.
Cali police Colonel Hoover Alfredo Penilla said officers captured a suspect after the shooting, which happened at around 9pm on Friday in the club La Barra de la 44.
Edward Rodriguez, an investigations director with Cali prosecutors, identified the suspect as 20-year-old Johan Alexander Mosquera.
Club bouncer Reynaldo Campos gave a different account of what he said was a 20-minute shoot-out. He said several men entered the club, shooting and searching its three floors.
Mr Rodriguez said the leading hypothesis was that the shootings resulted from a revenge attack launched by one criminal gang against another.