The National High Court will investigate the possibility of a cyberattack being behind this weeks massive blackout

Spain has launched an investigation into this week's widespread power outage to determine whether a cyberattack may have triggered the blackout that swept across almost the entire Iberian Peninsula.

The Spanish government declared a state of emergency on Monday after a midday outage struck Spain and neighboring Portugal, also briefly affecting parts of France. The blackout left millions without electricity, causing disruption on roads and at airports. While power has mostly been restored, transport services remain affected.

In a statement on Tuesday, Spain's High Court said Judge Jose Luis Calama had ordered preliminary proceedings to assess whether the blackout was the result of cyber sabotage.

The National Cryptologic Center, grid operator Red Electrica (REE), and the police have reportedly been instructed to submit reports within ten days detailing the causes of the outage and the events surrounding it.

Calama said that although the cause was still unknown, "cyberterrorism is among the possible explanations."

REE said on Tuesday that a cyberattack had been ruled out in its initial assessment. System Operations Chief Eduardo Prieto told a news briefing it was possible that the disruption involved solar generation, but that it was too early to draw conclusions.

Portugal's grid operator, Redes Energeticas Nacionais (REN), earlier said that a "rare atmospheric phenomenon" over Spain, triggered by "extreme temperature variations," may have caused the blackout.

Spanish officials have yet to confirm the cause. On Monday evening, Prime Minister Pedro Sanchez said there was no conclusive information.

Power has now been restored across almost all of Spain and Portugal, though both countries remain under states of emergency. On Tuesday morning, REE said electricity had been restored to 99% of Spain. The transport minister warned some trains, including high-speed rail services, would still run on reduced schedules.

Experts say it might take weeks to determine the exact cause of the failure. Some have pointed to Spain's increasing reliance on renewable energy, particularly solar power, as a potential factor.

Sanchez rejected the claims. "Those linking the blackout to the lack of nuclear power are either lying or demonstrating their ignorance," he said at a press briefing on Tuesday.

(RT.com)