Spain and Portugal have regained access to electricity after one of Europe’s worst blackouts paralysed transport systems, disrupted mobile communications and postponed medical procedures.

Electricity was restored to almost all of Spain and Portugal on Tuesday morning following a massive power cut affecting the entire Iberian Peninsula, but the cause of the blackouts remained a mystery.

See photos of the massive power outage that affected millions of people in Spain and Portugal due to an "induced atmospheric vibration."