Power started returning to parts of the Iberian peninsula late on Monday after a huge outage brought most of Spain and Portugal to a standstill, grounding planes, halting public transport, and forcing hospitals to suspend routine operations.

Spain and Portugal declared a state of emergency after an all-encompassing power failure struck those nations as well as Belgium, Andorra and France.

Several airports, including Madrid airport, which is Spain's busiest, had no electricity, El Mundo reported. Madrid's mayor, José Luis Martínez-Almeida, urged residents to limit their movements and stay off roads. Major cities including Barcelona, Seville and Valencia were without power. Parts of France were also affected by power loss.