Most of Spain and parts of Portugal and France experienced a major power outage on Monday afternoon, paralyzing public transport, causing massive traffic jams, delaying flights, and affecting power and phone lines.

Bloomberg reported that public transport, traffic lights, and phone services were disrupted in most parts of Madrid, Barcelona, and Lisbon due to the outage, while most train services came to a halt.

Utility companies sought to restart the power grid, but Spain's Red Eléctrica, the grid operator, said the cause of the outage was not yet clear, according to Reuters.

The blackout caused chaos in parts of Portugal and Spain, with traffic lights out of service, leading to a traffic crisis. Transport networks halted, hospitals lost power, and people were trapped in subways and elevators.

Sources familiar with the matter told Reuters that the Spanish and Portuguese governments met to discuss the power outage, which also briefly affected areas in France, and a crisis committee was formed in Spain.

Officials did not rule out the possibility that a cyberattack caused the blackout.

A widespread European problem

Spanish Prime Minister Pedro Sánchez visited the control center of Red Eléctrica.

The Spanish government said: 'We are working to identify the source of this crisis and its impact, and we are dedicating all resources to resolve it as soon as possible.'

The European Commission stated it is in contact with authorities in Spain and Portugal and the European Network of Transmission System Operators for Electricity (ENTSO-E) to try to determine the cause of the outage.

E-Redes, a Spanish electricity grid monitoring company, said in a statement that it is working to restore power gradually, adding: 'This is a widespread European problem.'

Portugal's REN said it has activated plans to restore electricity in stages.

Portuguese police said traffic lights were affected nationwide, the subway in Lisbon and Porto was closed, and trains stopped operating.

Residents of Andorra and parts of France bordering Spain also reported power outages, according to Euronews, with other outages recorded in areas as far as Belgium.

Power outages of this magnitude are rare in Europe. In 2003, a problem on a hydroelectric power line between Italy and Switzerland caused a major blackout across the Italian peninsula lasting about 12 hours.