Quintana Roo State Attorney General Miguel Angel Pech told a press conference that two Canadians, an Italian and a Colombian were killed. A woman died in the stampede to exit the club.
The Canadian government confirmed that one of its citizens had died and said it was investigating the reports of a second Canadian death.
Pech said the incident began when a person entered the Blue Parrot nightclub armed around 3.00 a.m. on Monday morning, during the closing of the festival. Another person tried to stop the person, sparking a gunfight that drew in security staff.
The shooting represents a major blow to Mexico's tourism industry, which has been one of the few bright spots in the economy thanks to a weak peso exchange rate.
Pech added that 15 people were injured, of whom 10 are still in hospital. The state government said in a statement that one person was in grave condition. Four people were arrested on suspicion of being involved in the incident.
Pech said two of the dead were BPM security workers but the festival said in a statement that three members of their security team were killed. BPM said the shooting was carried out by a lone shooter.
Quintana Roo and the surrounding Yucatan peninsula have traditionally been less violent than other parts of Mexico, with relatively low murder rates. However, with many foreign tourists and a vibrant night life scene, there has long been an important local drug market in and around Playa Del Carmen.
Videos purportedly shot at the scene shown on television and social media appear to show dancers ducking for cover and running out on the streets to safety.
"This is a very, very sad situation. Tryna get my head around it still. Thoughts and condolences to all affected," Scottish DJ Jackmaster, who was performing at BPM, said on Twitter.
The BPM festival, which was entering its 10th year, has grown to be one of the biggest electronic music events in the world, with top DJs flying in every January to play the clubs of Playa del Carmen along Mexico's Caribbean coast.
In recent years, Mexico's Caribbean coast has drawn a growing number of DJs and fans of electronic music to the beautiful, balmy region, looking to escape the frigid European and North American winters.
Banner/Thumbnail Photo Credit: Reuters, Stringer