MEXICO CITY _ It was supposed to be the celebratory finale of a 10-day international electronic music festival known as BPM, for Bartenders, Promoters, Musicians.
Instead, authorities said, the party became a bloodbath as a shootout left at least five people dead, 15 injured and temporarily transformed a portion of the tourist destination of Playa del Carmen on Mexico's "Mayan Riviera" into a scene of chaos and panic.
The shooting _ precipitated early Monday by a lone gunman at the entrance to a club called the Blue Parrot, according to Mexican authorities _ was also an unusual instance of Mexico's entrenched violence intersecting with the nation's tourist industry and its often-raucous bar scene.
Playa del Carmen and other popular tourist destinations have generally been spared the violence, often drug- and gang-related, that has ravaged some parts of Mexico.
Police ruled out terrorism as a motive in Monday's shooting at the beachside bar about 40 miles south of Cancun along Mexico's Caribbean coast.
The music event attracted large numbers of U.S. citizens and other foreigners.
Among the dead were two Canadian nationals, an Italian and possibly a Colombian, authorities said. Victims included both private security personnel at the scene and club patrons, authorities said.
At least one person, a woman, was fatally injured in a "stampede" of people fleeing the club, according to Miguel Angel Pech, attorney general of Quintana Roo state, where Playa del Carmen is situated. She and other victims were not publicly identified.
Video posted on social media purported to show panicked patrons fleeing from the club as the shooting occurred shortly before 2:30 a.m. _ a time when, police said, the dance venue was "saturated" with revelers.
The injured included at least two U.S. residents and one Canadian, Pech, the security official, told reporters.
The violence apparently began when a man with a gun became involved in an altercation with security personnel, who also appeared to have been armed, Pech said. It was unclear how many people opened fire. The precise motive for the attack remained unclear.
Three people arrested nearby were in custody, the state official said, but it was not confirmed if the alleged instigator was among them. He was not among the dead, said Pech, who added that he appeared to have fled the scene.
Police found at least 20 bullet shells at the venue from at least three different weapons, the state official said.
In a statement, organizers of the well-publicized event said the violence erupted in front of the club and confirmed that the fatalities included three members of the event's security team.
Organizers blamed a "lone shooter" and condemned "this senseless act of violence" at the event, which was billed as an annual, post New Year's electronic music festival held at various venues in Playa del Carmen and attracting thousands of revelers.
