Fourth person arrestedpublished at 12:53 British Summer Time 18 August 2017Breaking
Spanish police, external say a fourth person has been arrested in relation to the attacks in Barcelona and Cambrils.
14 killed and dozens injured in attacks in Barcelona and Cambrils
Van crashed into crowds at Barcelona's tourist hotspot Las Ramblas, killing 13
Five suspects shot dead by police in Cambrils, south-west of Barcelona, after another car attack killed one and injured six
Key suspect in Barcelona attack, Moussa Oukabir was among those killed in Cambrils, police confirm
Four other people have been arrested, one suspect still on run
Citizens of some 34 countries killed or injured
David Walker and Kelly-Leigh Cooper
Spanish police, external say a fourth person has been arrested in relation to the attacks in Barcelona and Cambrils.
France has strengthened its controls along the border with Spain.
French Interior Minister Gerard Collomb said the decision was made in light of the fact a suspect was still on the run.
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Barcelona is about 100 miles (160km) from the border.
A total of 130 people were injured across the attacks in Barcelona and Cambrils, according to the Spanish emergency services.
Thirteen people died after a van drove at pedestrians on Las Ramblas in Barcelona. Another person died following a second attack in the seaside town of Cambrils.
Georgie Thomas, who lives in Barcelona, describes the atmosphere after deadly terrorist attacks.
Read MoreSpanish emergency services have released a list of the 34 nationalities of those who were injured and killed in the attacks.
They include: Germany, Belgium, Egypt, Spain, Italy, France, Pakistan and the UK.
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A grandfather has launched a desperate plea to find his grandson, who has not been seen since the Las Ramblas attack.
Tony Cadman shared a picture of Julian Cadman on his Facebook:
His daughter-in-law and grandson were in the city for a wedding.
Julian's father, Andrew, had remained behind in Sydney. He is understood to be travelling to Spain currently.
A friend told local radio staton 2GB, external he is "absolutely beside himself".
Frank Gardner
BBC Security Correspondent
The practice of using a large vehicle as a weapon to attack pedestrians is not new.
Palestinian militants have used it against Israelis, al-Qaeda encouraged its followers to do it seven years ago in its online magazine.
But the recent spate of lethal attacks in European cities stems in large part from a call made in 2014 by the now-deceased Islamic State propagandist, Abu Mohammed Al-Adnani.
He urged IS's followers to abandon elaborate plots in favour of simple, low-tech, high-impact attacks in the West.
He specifically mentioned vehicles. Now, with IS coming under massive pressure in the Middle East, where its caliphate is shrinking by the day, its remaining leaders are more determined than ever to strike back at those countries they blame for the end of their brutal rule.
So the onus will now be on governments to second-guess where violent jihadists may be tempted to strike next and put measures in place to stop them.
Emergency services in Catalonia have said those killed and injured in the attacks are of "34 different nationalities", based on a provisional assessment.
The Catalan government previously said people of 24 nationalities were involved.
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The victims of attacks in Barcelona and Cambrils come from over 20 different countries, officials say.
The victims of attacks in Barcelona and Cambrils come from 34 different countries, officials say.
Read MoreDefiant crowds gathered at the top of Las Ramblas to observe a minute's silence
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Flags are lowered across Europe following the attacks in Spain
The Foreign Office has said it is assisting a "small number" of British people injured in the attacks in Spain and is trying to establish if any more need help.
"We have deployed additional staff to Barcelona and have offered support to the Spanish authorities," it said in a statement.
Its helpline for people calling from Spain is 112 and 012.
For people calling from outside Spain, the number is +34 93 214 21 24 and +34 900 400 012.
Today Programme
BBC Radio 4
Police have confirmed they are looking for Moussa Oukabir, the brother of Driss Oukabir who was arrested in Ripoll, El Pais reports, external.
It has not been confirmed that Moussa was the driver of the van in Barcelona, police added.
Emergency services have confirmed that the death toll has risen from 13 to 14 following the attacks in Barcelona and Cambrils. A woman injured in the Cambrils attack was the 14th person to have died, they said.
She is the first victim to have died in the Cambrils attack.
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BBC Monitoring
The world through its media
Spain’s El Periodico , externalsays security is being stepped up in Madrid, with large posts put up to block traffic access around the busiest pedestrian zones of the city.
El Confidencial, external reports a strong police presence at the entrances to the Guggenheim Museum in Bilbao.
El Pais , externalsays the country’s terror risk level will be assessed on Saturday at a meeting called by the Interior Ministry. Currently, it is at four on a scale of five.
A minute's silence in memory of the victims of the Spanish attacks has just been held across the country.
Crowds, joined by King Felipe VI, gathered with Catalan flags at the top of Las Ramblas to pay tribute.
Loud applause followed the silence for several minutes.
Francisco López Rodríguez, has been named, external as one of 13 people who were killed in the attack in Barcelona on Thursday.
El Pais said the 60-year-old was from Granada. His wife was seriously injured and her niece and youngest son were also killed, the paper adds.
A man who filmed the shooting in Cambrils described what he saw.
A man who filmed the shooting in Cambrils described what he saw.
Read MorePeople have been gathering at the site of the attack in Barcelona to pay tribute to the victims.
Many have been laying flowers, candles and other items at the site.
A minute's silence is to be held across Spain at 11:00 BST (12:00 local time) and the country will observe three days of national mourning.