Millions of people in Spain, Portugal, and Andorra were left without electricity today following a major power outage, Euronews reported. According to Agence France-Presse, parts of southern France were also affected by the blackout.

The exact cause of the outage remains unknown. Portuguese authorities confirmed that a nationwide power failure occurred around 12:30 p.m. local time. Similar reports have been received from Spain, although the Balearic and Canary Islands have not been impacted.

Spain's national grid operator stated that efforts are underway to restore electricity and determine the cause of the disruption. While a cyberattack has not been ruled out, a technical malfunction is also considered a possible explanation.

The blackout has led to significant disruptions, with Madrid's Barajas International Airport and Lisbon Airport among the major infrastructures left without power. Telecommunications services in both countries have also been affected.

Traffic systems have been severely impacted, with traffic lights turning off and metro and train services halted across Spain and Portugal, according to Politico. In hospitals, generators have been activated to maintain essential operations, and staff have been instructed to shut down computers as a precaution, given the uncertainty over when power might return.

Authorities have urged the public to avoid calling emergency numbers, which are overwhelmed. Meanwhile, long queues have been observed at ATMs and bus stops as residents adapt to the blackout conditions.

Portugal's electricity network operator reported that the outage appears related to an issue with the European grid, most likely a voltage imbalance. Politico added that Spain and Portugal's energy networks are highly interconnected and function as an "energy island," relying on limited cross-border connections to the broader European system.