A train carriage was left in darkness during a power outage in Spain.

Chilling footage shows a darkened Metro Valencia train amid the massive blackout on April 28.

The electrical disruption halted public transportation, leaving thousands of commuters stranded in underground stations and aboard immobilised vehicles.

Officials said the electricity cut was part of a major grid failure that impacted large parts of Spain and Portugal.

The country declared a state of emergency. More than 30,000 police officers were deployed to deal with the mayhem caused by the power failure.

Spain's reliance on solar and wind was said to have exacerbated the power cuts because the renewables can make the grid less stable.