An investigation has been launched after at least 12 people died and dozens more were injured after a crush at a football stadium in El Salvador's capital, San Salvador, officials have said.

The incident occurred during a match between local team Alianza and the Santa Ana-based team Fas at Cuscatlán Stadium. The match was subsequently suspended.

President Nayib Bukele described the event as "unprecedented" and said an "exhaustive investigation" would be launched. President Bukele said "everyone" will be investigated, including teams, managers, stadium officials, the league and the federation. He said in comments posted to Twitter by his press secretary:

Whoever the culprits are, they will not go unpunished.

Police had earlier said that seven men and two women were among the dead, with all the victims over the age of 18.

The disaster reportedly occurred after a large number of fans tried to enter the venue after the gates had been closed, the BBC reported.

Officials believe some fans had been sold fake tickets and said that an investigation was under way.

Footage shared by local media appeared to show fans attempting to pull down barricades at the stadium's entrance.

A livestream of the match posted on YouTube shows the match being suspended after an apparent commotion in the stands. People are later seen being carried away by emergency services on stretchers.

Fans are also seen waving their shirts at people on the ground to try and cool them down.

A volunteer with the Rescue Commandos first aid group told journalists:

It was an avalanche of fans who overran the gate. Some were still under the metal in the tunnel. Others managed to make it to the stands and then to the field and were smothered.

Officials also said that 90 people were being given medical attention, and that men, women and children had been treated for "multiple traumas".

Luis Alonso Amaya, from the Civil Protection of El Salvador, said that about 500 people had been given medical treatment, with many transferred to hospital.

Image: By JMRAFFi - Own work, CC BY-SA 4.0,