Five killed in Portugal blast

MADRID, Spain (CNN) -- An explosion at a fireworks factory has killed five people and injured one at the northern Portuguese city of Guimaraes, authorities said.

The blast occurred shortly after noon on Friday in an outlying district of Guimaraes known as Caldas das Taipas, where the factory was located in a remote field.

The explosion destroyed the factory but did not affect any other buildings, the state news agency Lusa told CNN.

A Public Security Police office in Lisbon confirmed the number of casualties.

The seriously injured person was taken to hospital in Guimaraes, a city of 150,000 people located some 50 km (30 miles) north of Oporto, Portugal's second-largest city.

Blasts common

Firefighters backed by two helicopters and 14 vehicles battled a blaze around the factory, which had spread to forested land.

No immediate cause was given for the explosion, and factory's name was not available. Lusa reported that authorities were trying to determine how many workers were in the factory at the time of the blast.

Such explosions are common in Portugal, especially in the north, where there are many small factories making fireworks. The blasts often occur in summer, when plants produce fireworks for parties and festivals.

Antonio Rodrigues, president of the Portuguese Fireworks Industry Association, said the sector needed to improve security measures.

"We have no support of any kind from local governments or the police for training," he told Reuters.