A fire that broke out in a nightclub in the southeastern Spanish city of Murcia has left 13 people dead and injured several others, authorities said. 

The fire started around 6am on Sunday (local time) in the popular Teatre nightclub and quickly tore through the venue, according to Spain’s state news agency EFE. 

The blaze broke out in the Fonda Milagros nightclub - known as La Fonda - and then spread to neighbouring clubs as patrons rushed to escape the packed dancefloors, police said. 

It was not immediately clear what caused the fire. 

A video shared by Murcia’s fire service showed firefighters trying to control flames inside the nightclub. Police and emergency services worked to secure the interior of the club to avoid a possible collapse and were trying to locate and identify the bodies. 

Firefighters outside La Fonda nightclub in Murcia, southeastern Spain, in the early hours of Sunday. Photo / AP 

Officials said the death toll could increase. 

The city council declared three days of mourning, with flags flown at half-mast on public buildings throughout the region of Murcia.