Red Eléctrica, Spain’s electricity grid operator, ruled out a cyberattack, human error or unusual weather. Experts say it could take weeks to determine the cause.

A huge power cut across Spain and Portugal left millions of people stranded on trains and airport floors. A state of emergency was declared in Madrid after large swathes of the population had no power

Spain and Portugal have been hit by a power outage covering wide areas across the two countries. Capitals Madrid and Lisbon are included in the outages as grid operators work to resolve the issue. Spanish power grid operator Red Electrica said it was working with energy companies to restore power in affected areas.