Portuguese National Cybersecurity Centre said there was no sign of a cyberattack

Agencies Madrid 

A blackout brought much of Spain, Portugal and parts of France to a standstill Monday, halting subway and railway trains, cutting phone service and shutting down traffic lights and ATM machines for the 50 million people who live across the Iberian Peninsula. 

Spanish power distributor Red Eléctrica said that restoring power fully to the country and neighbouring Portugal could take 6-10 hours. By mid-afternoon, voltage was progressively being restored in the north, south and west of the peninsula, the company said. 

The company declined to speculate on the causes of the huge blackout. The Portuguese National Cybersecurity Centre issued a statement saying there was no sign the outage was due to a cyberattack.  Eduardo Prieto, head of operations at Red Eléctrica, told journalists it was unprecedented, calling the event "exceptional and extraordinary."

The outage hit across Spain and Portugal, including their capitals, Madrid and Lisbon. Offices closed and traffic was snarled as traffic lights stopped working. It was not possible to make calls on some mobile phone networks, though some apps were working. In Barcelona, residents walked into stores searching for battery-powered radios and civilians directed traffic at junctions along the Gran Via avenue that cuts through the city. 

The countries have a combined population of over 50 million people. It was not immediately clear how many were affected.  It is rare to have such a widespread outage across the Iberian Peninsula.