Five people have been killed and two others injured in an explosion at a fireworks factory in Sicily.Italian police said the 71-year-old wife of the owner of the family-run business was among the victims.Her son - who tried to save his mother - was seriously hurt and was taken to hospital for treatment for severe burns, La Repubblica reported.The blast happened on Wednesday afternoon in the town of Barcellona Pozzo di Gotto, situated around 25 miles from the harbour city of Messina in northeast Sicily.Police said it was possible staff may have accidentally triggered the explosion with welding equipment.

An investigation has been launched into the cause of the blast.Sixty-eight people have been killed in explosions at fireworks firms since 2000, according to Italian consumer group Codacons.Safety issues at such plants have long been debated in Italy, where the production of fireworks is often a family-run business.