The number of people killed in a huge fireworks factory explosion in north-eastern Spain has risen to six after the body of a missing man was found.

The body was found close to the Pirotecnia Zaragozana factory in the small town of Pinseque where the explosion occurred on Monday, according to a regional interior ministry spokesman.

He said the six dead were two women and four men with links to the factory.

Six others injured in the blast are being treated in two hospitals in the nearby regional capital of Zaragoza. He said two of them are in a serious condition.

Zaragoza city declared a day of mourning and the mayor called for people to gather for a minute's silence outside the town hall.

Police are investigating the cause of the explosion. Initial investigations were hampered by a series of smaller blasts and fires after the main explosion.