The shooting was outside the Blue Parrot nightclub during part of the BPM electronic music festival, Mexican police said on Monday.

The BPM Festival posted a statement saying four people had been killed and 12 injured and that the attack had involved "a lone shooter." The death toll was later updated to five, including two Canadians, an Italian and a Colombian, according to local authorities. The Canadian government confirmed that one of their citizens had been killed, and said it was investigating reports of a second death.

Mayor Cristina Torres told Turquesa radio that 15 people had been injured, some in a stampede. One of the fatalities occured as a result of the stampede. Later on Monday, officials said that 10 people were still in the hospital, one in a grave condition.

A gunman reportedly fired shots through an open window just after 3 a.m. local time (0800 UTC) on Monday. Local news reports suggested that the shooting was connected to ongoing drug cartel wars in the area.

Playa de Carmen lies on Mexico's Yucatan peninsula, filled with popular tourist destinations

Shooter still at large

The shooter was possibly still at large on Monday morning, although Quintana Roo state attorney general Miguel Angel Pech said four people had been detained nearby. He added, however, that it was too soon to say if they had been involved in the shooting.

According to Pech, the incident was not being treated as terrorist attack. He said that a single assailant had entered the club and reportedly began to exchange fire with another indvidual inside. Quintana Roo state police chief Rodolfo del Angel also said that the incident was likely sparked by "a disagreement between people inside" that drew in the event's security personnel.

Pech announced that two of victims had been BPM security guards, though the festival's statement said that three members of its team had lost their lives.

BPM also said that "the violence began on 12th street in front of the club and three members of the BPM security team were among those whose lives were lost while trying to protect patrons inside the venue."

The club is one of the venues for the 10-day festival in the town, which has largely been spared the violence that has hit other parts of Mexico. The event organizers told Reuters news agency that the security situation in wealthy Quintana Roo had become more precarious since the politcal party that used to run the region was forced out in last year's local elections. This has sparked violence amongst local drug gangs as they sought to realign their interests with new political power-players.

jbh, es/se (AP, AFP, Reuters)