Madrid, 28 April 2025 (dpa/MIA) - A massive power outage that has caused chaos in Spain and Portugal is beginning to be fixed but many remained without electricity on Monday.

Work on restoring power to some 10 regions in Spain is progressing, the Spanish electricity grid operator Red Eléctrica said on X.

The regions of Catalonia, Aragon, the Basque Country, Galicia, Asturias, Navarre, Castile and Leon, Extremadura and Andalusia are seeing power slowly resume.

This follows an announcement from the company that said the power supply had been restored in several areas in the north, south and west.

Spanish Prime Minister Pedro Sánchez called on citizens to remain calm.

"We will experience some critical hours until the power supply is restored," he said in a televised address which not all the public could see.

Sánchez urged people to make only brief and urgent phone calls and to use the emergency number only when strictly necessary.

The government is in contact with the royal household, parliamentary parties, European partners and NATO, he said.

"The priority is to ensure that normality is restored," assured the social democrat.

Sánchez added that the restoration of power in the northern and southern regions of the country had been achieved thanks to cooperation with authorities in France and Morocco. He thanked the countries for their solidarity.

Medium- and long-distance trains in Spain remained out of service and it was "not expected" that they will resume on Monday, Transport Minister Óscar Puente said on X.

The cause of the outage has not been announced.

According to El País newspaper, which said it could take 10 hours for the blackout to be completely over, the INCIBE cybersecurity authority is investigating the incident and has not ruled out a cyberattack.

However, there is currently no indication that a cyberattack is the cause, European Council President António Costa wrote.

"Grid operators in both countries are working on finding the cause, and on restoring the electricity supply," the Portuguese added.

Reporters from dpa in Madrid and Barcelona said the outage was across both cities, with the Madrid Open tennis tournament also suspended.

Infrastructure, phone networks and traffic were all affected, as traffic lights turned off and lifts became stuck.

Spain's Health Ministry said hospitals were not as severely hit thanks to backup generators.

In neighbouring Portugal, there was a blackout in several areas, broadcaster RTP reported.

Spain's Canary and Balearic Islands were not affected, while a power outage in neighbouring Andorra lasted only a few seconds before the grid was automatically reconnected to the French grid, operator FEDA said on X.

Parts of France's Basque region were also affected for a short time before power was restored.

The European Commission said it is in contact with Spanish and Portuguese authorities.

"The commission is in contact with the national authorities of Spain and Portugal ... to understand the underlying cause and the impact of the situation," a spokeswoman said in Brussels.

"There are protocols in place to restore the functioning of the system," she added.

Photo: MIA Archive