At least one person died in the crush to escape and some of the 15 people wounded or injured were hurt in the rush out, authorities said.

Quintana Roo state Attorney General Miguel Angel Pech ruled out any terror attack, and the state's governor said it involved a personal dispute. Pech said the shooting erupted when security personnel tried to stop a man from entering the Blue Parrot club with a gun.

Three of those killed were part of the security detail at the 10-day BPM electronic music festival, Pech said. The gunman apparently fled.

"I was thinking it was the same thing that happened in Paris, some guy just walking in and shooting people at a restaurant, bang bang bang, a terrorist attack," said New Zealand tourist Tyler Klee, who was outside the club when shots rang out.

"Everyone ran, everyone was terrified, looking for their friends ... We were running away and then you hear more shots fired, like you don't know if you're going to be shot in the back or not."

His friend Ben Forbes, from Australia, said: "It happened pretty quickly as well ... You still didn't know where they were, how many there were."

Officials released a list of the dead, who included one Canadian, one American, two Mexicans and one Italian.

Canada's Global Affairs Department identified its dead citisen as Kirk J. Wilson of Toronto.

Neil Forester, a friend, said Wilson was a longtime bouncer and was working security at the festival to lend a hand to its Canadian organisers. "He was just a genuine, one-of-a-kind guy," Forester said. He said Wilson was 49 and was married with two children.

The US Embassy confirmed that one of those killed was a US citisen, and the Quintana Roo state prosecutor's office identified her as Alejandra Villanueva Ibarra. The office said she died in the crush to escape the shooting.

Italy's Foreign Ministry confirmed one of its citisens died, and the prosecutor's office identified him as Daniel Pessina and said he was part of the BPM staff.

The Mexican victims were identified as Rafael Penaloza Vega and Geovanni Ruiz Murillo. The prosecutor's office said Ruiz Murillo was wearing a BPM shirt.

Pech, the state attorney general, said a Mexican woman was seriously injured. He said eight of the injured were treated at hospitals for lesser injuries and released.

The shooting occurred near the largest exit, setting off chaos as concert goers had to scramble over a metal fence to escape to the beach.

Jeffrey Castelein, 33, a fork lift operator from Belgium, said he heard 15 to 20 shots before he and his friends leapt the fence. "At first we didn't realise, and then everybody fell down and you had to hide a little bit. And then we went out the back by the sea."

Pech said the shooter apparently tried to enter the nightclub about 2:30 a.m., but was denied access because he had a gun. He then began to exchange fire with another person, and festival security personnel who tried to stop the shooting came under fire, Pech said. He said 20 bullet casings apparently from three different pistols were found at the scene, but it was unclear if the security detail was armed or fired any of the weapons.

Pech said three people were detained nearby. It was not known if they had been involved in the shooting.

"We know of another shooting incident that occurred near the nightclub, but we are investigating whether that is related" to the deadly shooting, Pech said.

Quintana Roo Governor Carlos Joaquin attributed the shooting to "the intolerance and conflict of interests between two people," and also referred to it as "a personal conflict" between two people who exchanged gunfire. But he did not specify what the conflict was.

Playa del Carmen has largely been spared the violence that has hit other parts of Mexico.

The state tourism department said the shooting was an "isolated act of violence" and stressed that "the situation in Playa del Carmen is under control and Mexican and foreign tourists can feel protected and safe."