MADRID/LISBON -- A massive blackout swept across Spain and Portugal on Monday, leaving large parts of both countries without electricity and causing widespread disruption.

Spain's electricity grid operator, Red Electrica, confirmed widespread power outages across the country. The company said it was working to restore electricity supplies and to analyze the causes of the blackout. "All resources are being dedicated to solving it," Red Electrica said in a post on X.

Following the outage, Spanish Prime Minister Pedro Sanchez visited Red Electrica's control center to oversee recovery efforts. His office stated that "the government is working to find out the origin and the effects of this incident and is dedicating all its resources to solving it as soon as possible."

In Madrid, the immediate effects were visible when traffic lights across the city simultaneously stopped working, leading to chaos on the roads. Metro services in Madrid and Barcelona were also brought to a standstill, leaving thousands of passengers trapped inside tunnels.

Spain's national railway company, Renfe, reported that the national electricity grid was cut off at 12:30 pm local time, forcing train operations across the country to come to a halt. "Trains stopped" and there were "no departures" at any stations, the company said.

Reports also emerged of people trapped inside elevators in office buildings and apartment complexes. Marie-Carmen Sanz, a hospital worker at Madrid's Ramon and Cajal Hospital, told Xinhua that several hospital workers and patients were trapped in elevators at the facility.

In Portugal, the blackout extended from north to south, affecting cities including the capital, Lisbon, where life came to an abrupt halt. Multiple trams stopped operating in the city center at midday, causing severe traffic congestion.

Fernanda Picarra, a tourist from Aveiro, recounted her experience after her tram suddenly stopped. "At first, we thought the tram had broken down," she said. "We waited on board for a long time before noticing that several other trams had also stopped. Eventually, the driver asked everyone to disembark."

Banks, restaurants, and cafes across Lisbon were plunged into darkness, forcing businesses to close and sending large crowds onto the streets. Bank staff were seen explaining to customers that services would remain suspended until power was restored.

Taxi driver Pedro, who kept his radio tuned to the news, noted the scale of the outage. "It's a massive blackout - Spain and Portugal are both down, and it seems France is affected too," he said. Pedro, who recalled a similar blackout more than 20 years ago, added, "I've been listening to the news all day, but no one seems to know exactly what happened. I just hope things return to normal soon."

Following the power failure, Lisbon's metro system also came to a halt, with reports of passengers trapped inside trains. Mobile voice calls were disrupted across parts of Portugal, although data services remained operational.

Authorities in both countries continue to investigate the cause of the blackout as efforts to restore full electricity supply are underway.

The outage briefly affected parts of France, but the French electricity transmission system operator RTE announced on Monday afternoon that all affected households had regained access to electricity.

"In France, homes were without power for several minutes ... All power has been restored," the company said in a statement on its official X account.