MADRID - At least five people died and another six were injured on Monday in an explosion at a fireworks factory in northeastern Spain, local authorities said.
Two of the injured in the blast at the factory on the outskirts of Zaragoza near the city's airport are in intensive care, the regional government of Aragon said in a statement.
The cause of the explosion was unknown.
Emergency services warned local residents to stay away from the area.
"It is still dangerous to approach the area because there are still remains of fireworks that can explode," a spokesman for the fire service said.
Spanish television images showed plumes of black smoke rising from warehouses.
The regional government of Aragon declared a day of mourning.
Founded in 1860, the Pirotecnia Zaragozana company employs over 40 people and exports fireworks mostly to Europe and Canada, according to its website.
August is a busy time for fireworks factories in Spain as many small towns celebrate religious festivals at this time of year with fireworks shows.