MADRID, Spain -- A huge explosion Monday at a fireworks factory in northeastern Spain killed five people and injured six others, authorities said.
The blast occurred around 2 p.m. (1200 GMT) at the Pirotecnia Zaragozana factory in the small town of Pinseque, sending a dense plume of white smoke into the sky that could be seen for kilometers (miles).
The injured were taken to a hospital in the nearby regional capital of Zaragoza, said Gustavo Alcalde, the central government's top Interior Ministry official for the region.
A police spokeswoman said that three of those injured were in serious condition. She spoke on condition of anonymity because of department rules preventing her from being named.
Police and firefighters didn't know the cause of the blast and were prevented in initial efforts from trying to investigate it because fires were still raging at the site hours after the explosion and a series of smaller blasts.
Spanish national television said the blasts in the aftermath of the main explosion also hindered a search operation for people missing immediately after the incident.
By late afternoon, no more people were reported as missing, the spokeswoman said.
The factory was purchased in January by Etienne Lacroix Group and the French company said at the time that the plant's Spanish management team would continue running the business.
A woman who answered the phone at Etienne Lacroix said the company based near Toulouse had no immediate comment and referred inquiries to a company manager who did not immediately respond to an emailed message seeking comment.
Huge blast at Spanish fireworks factory kills 5, wounds 6