Spain and Portugal have been hit by a massive power outage that has caused blackouts, Spain’s electricity network operator has said.

The Spanish grid operator Red Eléctrica said it had activated plans to restore the supply, with “all resources dedicated to solving” the disruption.

It said the Iberian peninsula, with a combined population of more than 50 million people, had been affected.

Spain’s public broadcaster RTVE said the outage had hit several regions of the country at about 12.30pm local time, leaving its newsroom, Spain’s parliament in Madrid and metro stations across the country in the dark.

People in neighbourhood WhatsApp chats in Barcelona and cities and towns in its outskirts also reported the outage.

Fans at the Madrid Open tennis tournament after matches were suspended due to the power outage. Photograph: Violeta Santos Moura/Reuters

In Portugal, a country of about 10.6 million people, the outage hit the capital, Lisbon, and surrounding areas, as well as northern and southern parts of the country.

The Portuguese distributor E-Redes said the outage was due to “a problem with the European electricity system”, according to the Portuguese newspaper Expresso.

The company said it was compelled to cut power in specific areas to stabilise the network, according to Expresso.

A bar in the Spanish city of Toledo after a blackout hit. Photograph: Ismael Herrero/EPA

It was not possible to make calls on mobile phone networks, though some apps were working.

Unconfirmed news reports said the Lisbon subway had stopped running. Traffic lights in the city centre stopped working.

More details soon …