At least 15 people died and 35 were injured when a fire ignited by fireworks swept through a crowded Quito nightclub in Ecuador on Saturday, emergency officials said.

Rescue workers continued to search for bodies after the fire, among the worst in a decade in the hilly capital, where restaurants and clubs often lack proper emergency exits.

"Somebody set off fireworks inside the place which caused the fire," Quito fire chief Jaime Benalcazar told a local radio station. "The exit doors were locked with a padlock."

Firefighters used axes and sledge hammers to break down walls to help people flee the club packed with 300 people, some of them teenagers, watching a rock group, witnesses said.

"People were screaming for help. We tried to tear down the walls, but we couldn't," Giovanni Vargas, a 21-year-old who was near the club when the fire started, said.

"Lots of people died and you feel helpless because you couldn't help all of them."