Spanish officials have raised the number of people killed in a huge firework factory explosion in northeastern Spain to six after the body of a missing man was found.

A regional Interior Ministry spokesman said the body was found early Tuesday close to the Pirotecnia Zaragozana factory in the small town of Pinseque where the explosion occurred Monday.

He said six people were injured in the blast, of whom two are in serious condition.

Police are investigating the cause of the explosion.

The official spoke on condition of anonymity because of department rules preventing him from being identified.