"If the emergency exit had been open, so many people would not have died," Ibarra told reporters. He said the doors were "locked with chains and padlocks."

"This is a disaster. This is a disaster," a stunned Interior Minister Anibal Fernandez told reporters outside the discotheque.

Fernandez blamed the tragedy on overcrowding and also on blocked emergency exits at the club. The young people "were caught inside a mortal trap," he said.

He also confirmed that most of the concert-goers were aged between 12 and 20, but even some under 10 years old as some Argentine nightclubs provide nursery areas for customers with children.

The blaze, one of the worst in Argentine history, broke out before midnight Thursday at the Cro-Magnon Republic disco club in downtown Buenos Aires, Buenos Aires Health Secretary Alfredo Stein said.

Stein said 18 police officers were among the injured. Ibarra said 619 people were injured in the blaze.

The mayor said the blaze started when flares were tossed during the concert. "This is a terrible night," he told Todo Noticias television channel.

Bodies were lined up on the street as firefighters fought to put out the blaze. A chaotic scene unfolded outside the smolderng discotheque into early Friday, as hundreds of police and firefighters mingled with stunned teenagers and parents searching frantically for their children.

Some distraught and angry teenagers were seen on live television attacking television reporters and camera crews.

The revelers, mostly secondary school aged youngsters, were in the disco for a concert by rock group Los Callejeros.

A number of witnesses said the fire started when a flare set a curtain on fire, while others said it was the ceiling which caught fire.

"People fired the flares into the ceiling made of cloth and rubber," 15-year-old Cecilia Arce told reporters. "The rubber started burning but with few or no flames making a terrible smoke that choked you, killed you if you breathed it."

The spreading fire and smoke reduced visibility.

"Suddenly, we couldn't see anything because of the smoke and the fire spread to the stage area," another young man told a television reporter.

The witnesses said a mad dash for the exits began with hundreds of people pressing into each other.

Several people said an emergency exit was shut and that other entrances and exits to the club remained closed while the smoke filled the entire venue.

They said many of the victims died because in the confusion they unwittingly ran away from the exits.

"Many people were drunk and instead of running toward the five exits, they ran to the two upstair platforms where the bathrooms are located. There, they choked to death and were trampled," said Roberto Gutierrez, a waiter at a nearby cafe who ran inside the club to help the victims.

Fernandez said the club "was licenced to operate in theory, but in reality it only had two working doors. The other accesses were closed shut with wires. The youngsters were caught in a mortal trap."

"If the club had been evacuated in two minutes, nobody would have been hurt," the interior minister said.

Club owners had banned flares, issuing warnings over the loudspeakers that tossing flares was a criminal offense, witnesses said. Another youngster said there had been another fire at the Cro-Magnon Republic a week ago, but that nobody was hurt.

The injured were taken by dozens of waiting ambulances to nine public and private hospitals in the city.

In 1993, another end-of-term dance at the Kheyvis club in Buenos Aires also turned into a deadly inferno that killed 17 teenagers, including a pregnant girl.

La Nacion daily said the blaze was the third worst discotheque fire worldwide and the sixth worst for the number of victims it caused.