Portugal's prime minister also says there is no indication of a cyber-attack, as officials investigate what caused the power outages.

Several airports, including Madrid airport, which is Spain's busiest, had no electricity, El Mundo reported. Major cities including Barcelona, Seville and Valencia were without power. Parts of France were also affected by power loss.

Much of Spain’s power grid was operating normally on Tuesday, a day after a blackout affected critical infrastructure across the Iberian Peninsula.