A massive power cut hit large parts of Spain and Portugal on Monday, causing widespread chaos and disruption.

The outage left millions of people without electricity, while internet and phone networks were also down.

Trains were cancelled and evacuated in some regions, traffic lights stopped working amid mounting delays at airports.

With shops, homes and restaurants plunged into darkness - and some people stuck in lifts - Spain's electricity network said by mid-afternoon that restoring power could take several hours.

The cause remained unclear but there was "no indication" of a cyber attack, Portugal's Prime Minister Luis Montenegro said.

When did the outage begin?

The outage began around midday (13:00 BST) on Monday and its impact quickly escalated.

As the scale of the disruption became clear, residents of Madrid were warned to stay put, keep off the roads and not to call emergency services unless "truly urgent".

A Spanish operator said power restoration would take up to 10 hours, while Portugal's power firm REN said getting back to full power could take up to a week.

Queues formed at cash machines as card payments were affected by the outage, and there were reports that some petrol stations are closed.

Spanish media reported that some hospitals had implemented emergency plans, including halting routine work, news agencies reported.

By early evening and after several hours of blackouts, residents in some parts of the country reported the lights are back on.

Power was being restored "in several areas of the north, south and west of the [Iberian] peninsula", the Spanish grid operator said.

The authorities in Spain and Portugal are still trying to work out what caused the power cuts.

"There are no indications of any cyberattack" at this point, the President of the European Council, Antonio Costa, said.

As panic spread earlier in the day, residents of Madrid were warned people to stay off the roads.

In a video on social media, the mayor of the Spanish capital, José Luis Martínez-Almeida, told residents to "keep their movements to an absolute minimum and, if at all possible, to remain where they are. We want to keep all roads clear."

People should only call emergency services if it is "truly urgent", he said.

"If emergency calls go unanswered, go to the police and the fire stations in person, where they will try to deal with all the emergencies."

What has been the impact?

The country's nuclear power plants automatically stopped when the blackout hit, and the Spanish oil company Moeve said it halted operations at its oil refineries.

Flights were also impacted, with delays and cancellations at some airports. EasyJet said it was experiencing some disruption to operations at Lisbon and Madrid. It said the situation was "fluid" and told customers to check local advice.

Businesses have been severely affected. Some Ikea branches in Spain switched to backup generators and stopped customers from entering its stores.

The Madrid Open Tennis organisers have decided to cancel Monday's event.

Elsewhere, Andorra and parts of France were also hit, but the Balearic and Canary Islands were not affected.

• Were you affected by the outage? Email haveyoursay@bbc.co.uk

A child has damaged a painting worth millions of pounds by the American artist Mark Rothko at a museum in Rotterdam.

A spokesperson for the Museum Boijmans Van Beuningen said it was considering the "next steps" for the treatment of Rothko's Grey, Orange on Maroon, No. 8.

The damage occurred during an "unguarded moment", a museum spokesperson told the Dutch media outlet Algemeen Dagblad (AD) last week.

A spokesperson for the museum told the BBC the damage was "superficial", adding: "Small scratches are visible in the unvarnished paint layer in the lower part of the painting".

The abstract painting is estimated to be worth up to €50m (£42.5m), according to newspaper AD.

"Conservation expertise has been sought in the Netherlands and abroad. We are currently researching the next steps for the treatment of the painting", the museum spokesperson told the BBC.

"We expect that the work will be able to be shown again in the future," they added.

Sophie McAloone, the conservation manager at the Fine Art Restoration Company, said that "modern unvarnished" paintings like Rothko's Grey, Orange on Maroon, No. 8 are "particularly susceptible to damage".

This is "owing to a combination of their complex modern materials, lack of a traditional coating layer, and intensity of flat colour fields, which make even the smallest areas of damage instantly perceptible," she said.

"In this case, scratching of the upper paint layers can have a significant impact on the viewing experience of the piece," Ms McAloone said.

The Rothko painting was hanging in the museum's Depot – a publicly accessible storage facility beside the main museum – as part of an exhibition displaying a selection of "public favourites" from the gallery's collection.

Jonny Helm, a marketing manager at the art restoration service Plowden & Smith, said the incident had implications for UK institutions such as V&A East and the British Museum, which are considering "opening up the display of things that would otherwise be obscured in archives."

"How will this event affect other UK institutions who are opening up their archives in the same way?" Mr Helm said.

Restoring a Rothko painting is a difficult task because "Rothko's mixture of pigments and resins and glues were quite complex", Mr Helm said.

He said the fact the painting is unvarnished – meaning it is "open to the environment" – will pose an additional challenge to conservators.

Conservators working to restore the painting will now likely be in the process of documenting the extent of the damage and researching "historic successful treatments" of Rothko paintings.

"Rothko works seem to have terrible luck – this isn't the first damaged Rothko we've heard about," Mr Helm said.

Rothko's 1958 work, Black on Maroon, was deliberately vandalised by Wlodzimierz Umaniec at London's Tate Modern gallery in October 2012.

Umaniec was sent to prison for two years and subsequently apologised for his actions.

During his trial, prosecuting barrister Gregor McKinley said the cost of repairing the work would be about £200,000. It took conservators 18 months to repair the painting.

Rachel Myrtle, Head of Specie and Fine Arts at the insurance company Aon, said fine art insurance policies typically cover "all risks associated with physical loss and damage to artwork including accidental damage caused by children or visitors, albeit with certain exclusions".

She said that when an artwork is damaged, a gallery's insurer will appoint a specialist fine art loss adjuster to visit the museum.

The loss adjustor typically "reviews the damage to the artwork, examines any CCTV footage to determine the exact cause of the loss, and assesses conservation options", Ms Myrtle said.

The museum did not comment on who will be held liable for the damage to the 1960 painting, which the gallery reportedly bought in the 1970s.

The Museum Boijmans Van Beuningen has previously billed visitors who have caused damage to artworks on display.

In 2011, the museum asked an unsuspecting tourist who stepped on Wim T. Schippers' peanut butter floor artwork, called Pindakaasvloer, to pay for repairs to the work.

Sharon Cohen, a spokesperson for the museum at the time, was quoted by AD as saying: "It is normal procedure for people to pay if they damage art."

The Rothko painting is described by the museum as an example of colour field painting, a term used to describe art characterised by large blocks of flat, solid colour spread across a canvas.

Rothko's Grey, Orange on Maroon, No. 8 painting is one of several works of modern art that have been damaged in the Netherlands in recent years.

In November 2024, multiple screen prints by the US pop artist Andy Warhol were damaged by thieves during an attempted robbery of the MPV art gallery in the town of Oisterwijk.

In another incident, a Dutch town hall admitted it "most likely" disposed of 46 artworks by accident – including an Andy Warhol print of the former Dutch queen – during renovation works last year.

Museums have different policies when responding to damage caused by children.

In August last year, a four-year-old boy accidentally smashed a 3,500-year-old jar into pieces at the Hecht Museum in Israel.

At the time, Hecht Museum worker Lihi Laszlo told the BBC the museum would not treat the incident "with severity" because "the jar was accidentally damaged by a young child".

The family were invited back to the exhibition with his family for an organised tour shortly after the incident occurred.