Spain biodiesel plant explosion kills two

About 250 children who were out on a school trip were also brought to safety.

Videos made nearby and shared on social media showed a dense cloud of black smoke and flames after the blast that occurred at 1pm.

All of the police and firefighting units available were sent to the factory to fight the fire and ensure people were safe, the Calahorra local council said.

The authorities called on the public to avoid the area in case of further explosions.

It was not clear what caused the explosion in Calahorra about 300km northeast of Madrid.