The Mediterranean city is in mourning after a van ploughed into crowds on Las Ramblas boulevard last week.
Tens of thousands of Spaniards and foreigners staged a defiant march against terror through Barcelona on Saturday following last week's deadly vehicle rampages.
Red, yellow and white flowers -- the colours of Barcelona – were distributed to protesters and the slogan for the march will be "no tinc por" -- Catalan for "Not afraid".
The Mediterranean city is in mourning after a van ploughed into crowds on Las Ramblas boulevard on August 17, followed hours later by a car attack in the seaside town of Cambrils.
Fifteen were killed in the carnage and Spanish Prime Minister Mariano Rajoy has called on Spaniards to turn out in force to show their "love" and solidarity with Catalonia, where the rampages took place.
King Felipe VI will also attend the march, becoming the first Spanish sovereign to take part in a demonstration since the monarchy was re-established in 1975 after the death of dictator Francisco Franco.
TRT World spoke to journalist Marah Rayan for the latest.
Europe has been shaken by a spate of deadly Islamist violence with an increasing number of low-tech attacks using vehicles or knives -- sometimes both -- as weapons.
On Friday evening, a man was shot dead in central Brussels after stabbing a soldier and shortly afterwards another man with a large knife attacked police in London as they tried to arrest him outside Buckingham Palace.
'Love' for Barcelona
The Spanish premier said Friday the king would be attending the march to demonstrate "his love for the people of Barcelona, of Cambrils, of Catalonia.
"There, with all of Catalan society and all of Spain... we will once again give a clear message of unity and condemnation of terrorism, and of love for the city of Barcelona," he added.
The warm comments contrast with Rajoy's earlier criticism of Catalan leaders, with whom he has been at loggerheads over their plans to hold an independence referendum on October 1.
But in the aftermath of the attacks, which were claimed by the Daesh, he and Catalonia's separatist president Carles Puigdemont made a show of unity.
Already on Friday evening, thousands of people marched against terror in Cambrils, shouting "no tinc por", -- as Catalans shouted last week, immediately after the attacks.
Those who tended to the victims last week will be given pride of place at the top of the procession.
They include security forces, emergency workers, residents and shop owners in the Las Ramblas avenue and taxis who took people for free.
People like Montse Rovira, the 53-year old city hall's head of social emergencies, will also march at the head of the procession.
Her service helped people who were lost or who couldn't find their loved ones.
Over the following days, she and her colleagues gave families psychological support when they were given terrible news, and also helped others like doctors and firefighters.
"There are a lot of people who are suffering," she said, adding that even psychologists themselves had struggled.
Ode to peace
Saray Gomez, an 18-year-old who works at a flower stall right next to where the van ended its murderous rampage, said it was important "to give a message of unity and peace.
"And it's important to distinguish between Islam and jihadists, because Muslims are the first to be affected.
"The march will end at Plaza de Catalunya near Las Ramblas where two cellists will play "Cant dels ocells" (Song of the birds), a traditional Catalan melody which has become a symbol of peace.
It was famously played by the celebrated cellist Pau (Pablo) Casals, an outspoken opponent of the Franco regime, at the White House, in 1961.
Other marches also took place in cities around Spain, including Madrid, Valencia and Vigo.
Few tourists on the streets of Barcelona Saturday morning seemed to know about the march.
But Jesusa Solis, a 47-year old Filippina teacher said she had come from Madrid specifically to take part.
"We have to support each other against the violence," she said, referring to her home country's fight against terror groups.