At least 13 people have died and 100 have been injured after a van ploughed into a crowd of people in Las Ramblas area of Barcelona, in an attack that mirrors the spate of recent atrocities by terrorists who used vehicles to ram down civilians across Europe.

Catalan authorities confirmed that 13 people have been killed and 15 people are seriously injured following the attack in the area popular with tourists.

A Belgian national is among the dead, said Belgium's Deputy Prime Minister Didier Reynders.

Catalonia's Regional President Carles Puigdemont told a news conference two suspects have been arrested in connection with the attack.

Another man has been killed in a shootout with police on the outskirts of the city but it is unconfirmed whether he is one of the suspects.

It remains unclear how many attackers were involved in the terror attack.

Isis have claimed responsibility for the attack, the group's Amaq news agency said.

Police have released a picture of the man who allegedly rented the van used in the attack and is one of the two suspects arrested by police.

Spanish media named him as Driss Oukabir, who is described as a man in his twenties believed to be born in Morocco.

Two armed men were also reported to have entered a restaurant near the site of the crash, something which Catalan police later dismissed.

A second van linked to the attack has been found in the small town of Vic about 69 kilometres away from Barcelona, authorities have said.

The protocols for a terror attack have been activated.

The van entered the pedestrian street from Placa de Catalunya and reportedly zigzagged across the street before crashing into a kiosk on La Rambla.

The El Pais newspaper reported that the driver of the vehicle had fled on foot and that police are looking for a man about 1.70 metres tall, wearing a white and blue stripped shirt.

People are being evacuated from Las Ramblas area as police have launched a manhunt.

Meanwhile a driver has ran over two police officers at a checkpoint in Barcelona but it is unconfirmed whether the incident is linked to the van attack.

Police say a bomb squad is now checking an area on the outskirts of the city near where the drive struck the two officers.

Emergency services are urging people to avoid Las Ramblas area and requested the closure of nearby train and metro stations.

Ambulances and bomb disposal crews had gathered en masse at the scene.

(Graphic News (Graphic News)

Ethan Spidey, 25, told The Independent there was a “stampede” as tourists and locals sprinted away from the scene of the attack.

He said: “I was with my boyfriend just about to cross La Rambla and all of a sudden there was an immediate stampede and police shouting at people to run.

“I saw a young child knocked over and picked them up but everyone was just running.

“There was a stampede in the streets alongside La Rambla as everyone tried to run away. People were running into shops and taking refuge in cafes. There was a lot of screaming."

Daniela Goicoechea, who was walking along La Rambla with three children aged one, two and five, told The Independent: "People started running but we didn't know what was happening. There was a lot of people running. Then policemen began chasing people. We were lost, we ran with three babies and hid in a cafe nearby."

Videos posted on social media shows dozens of people, seemingly injured, lying on the floor being cared for by emergency services.

Around them, the boulevard was deserted, covered in rubbish and abandoned objects including hats, flip-flops, bags and a pram.

Hospitals in Barcelona have called for blood donations following the attack to avoid potential shortages.

Aamer Anwar was walking down La Rambla at the time, which he said was "jam-packed" with tourists.

He told Sky News: "All of a sudden, I just sort of heard a crashing noise and the whole street just started to run, screaming. I saw a woman right next to me screaming for her kids.

"Police were very, very quickly there, police officers with guns, batons, everywhere. Then the whole street started getting pushed back."

The incident took place at the height of the tourist season with Barcelona being one of Europe's top travel destinations with at least 11 million visitors a year.

A Foreign Office spokesman said: "We are in contact with the Spanish authorities and seeking more information following an incident in Barcelona.

"Anyone in the area should follow the advice of the emergency services."

Barcelona Attack Show all 30 1 /30 Barcelona Attack Barcelona Attack Police officers patrol on Las Ramblas following yesterday's terrorist attack, on August 18, 2017 in Barcelona, Spain. Thirteen people were killed and dozens injured when a van hit crowds in the Las Ramblas area of Barcelona on Thursday. Spanish police have also killed five suspected terrorists in the town of Cambrils to stop a second terrorist attack Getty Images Barcelona Attack Tourists and locals walk along Las Ramblas following yesterday's terrorist attack, on August 18, 2017 in Barcelona, Spain. Thirteen people were killed and dozens injured when a van hit crowds in the Las Ramblas area of Barcelona on Thursday. Spanish police have also killed five suspected terrorists in the town of Cambrils to stop a second terrorist attack. Getty Images Barcelona Attack Police officers patrol on Las Ramblas following yesterday's terrorist attack, on August 18, 2017 in Barcelona, Spain. Thirteen people were killed and dozens injured when a van hit crowds in the Las Ramblas area of Barcelona on Thursday. Spanish police have also killed five suspected terrorists in the town of Cambrils to stop a second terrorist attack. Getty Images Barcelona Attack People leave a fastfood with hands up as asked by policemen after a van ploughed into the crowd, killing two persons and injuring several others on the Rambla in Barcelona on August 17, 2017. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least two people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack" and a police source said one suspect had left the scene and was "holed up in a bar". The police source said they were hunting for a total of two suspects AFP/Getty Barcelona Attack Police officers tell members of the public to leave the scene in a street in Barcelona, Spain, Thursday, Aug. 17, 2017. Police in the northern Spanish city of Barcelona say a white van has jumped the sidewalk in the city's historic Las Ramblas district, injuring several people. AP Barcelona Attack Injured people react after a van crashed into pedestrians in Las Ramblas, downtown Barcelona, Spain, 17 August 2017. According to initial reports a van crashed into a crowd in Barcelona's famous Placa Catalunya square at Las Ramblas area injuring several. Local media report the van driver ran away, metro and train stations were closed. The number of people injured and the reasons behind the incident are not yet known. Official sources have not confirmed that the incident is a terrorist attack. EPA Barcelona Attack People flee the scene in Barcelona, Spain, Thursday, Aug. 17, 2017 after a white van jumped the sidewalk in the historic Las Ramblas district, crashing into a summer crowd of residents and tourists and injuring several people, police said. (AP Photo/Giannis Papanikos) AP Barcelona Attack People are pictured inside Systemaction, a locked down store after a van crashed into crowds on Las Ramblas in Barcelona, Spain, August 17, 2017. Courtesy Abbie Yermus/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS Barcelona Attack People take shelter inside a shop in Barcelona, Spain, Thursday, Aug. 17, 2017. A white van jumped up onto a sidewalk and sped down a pedestrian zone Thursday in Barcelona's historic Las Ramblas district, swerving from side to side as it plowed into tourists and residents. Police said 13 people were killed and more than 50 wounded in what they called a terror attack. (AP Photo/Manu Fernandez) AP Barcelona Attack People move from the scene after a van crashed into pedestrians near the Las Ramblas avenue Reuters Barcelona Attack A policeman stands next to an ambulance after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona AFP/Getty Images Barcelona Attack People are evacuated from a street after a van crashed into pedestrians near the Las Ramblas avenue in central Barcelona, Spain, August 17, 2017. REUTERS/Stringer NO RESALES. NO ARCHIVE. Reuters Barcelona Attack Firefighters stands outside an evacuated mall after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona AFP/Getty Images Barcelona Attack Policemen stand next to vehicles in a cordoned off area after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona AFP/Getty Images Barcelona Attack Plain-clothes policemen phone as they walk past police cars in a cordoned off area after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona AFP/Getty Images Barcelona Attack A policemen and a medical staff member stand past police cars and an ambulance in a cordoned off area after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona AFP/Getty Images Barcelona Attack A person is stretched out of a mall by medical staff members in a cordoned off area after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona on August 17, 2017. Police in Barcelona said they were dealing with a "terrorist attack" after a vehicle ploughed into a crowd of pedestrians on the city's famous Las Ramblas boulevard on August 17, 2017. Police were clearing the area after the incident, which has left a number of people injured. AFP/Getty Images Barcelona Attack Children, some in tears, are escorted down a road in Barcelona, Spain, Thursday, Aug. 17, 2017. Police in Barcelona say a white van has mounted a sidewalk, struck several people in the city's Las Ramblas district. AP Barcelona Attack Mossos d'Esquadra Police officers and emergency service workers move an injured man, after a van crashes into pedestrians in Las Ramblas, downtown Barcelona, Spain, 17 August 2017. According to initial reports a van crashed into a crowd in Barcelona's famous Placa Catalunya square at Las Ramblas area injuring several. Local media report the van driver ran away, metro and train stations were closed. The number of people injured and the reasons behind the incident are not yet known. Official sources have not confirmed that the incident is a terrorist attack. EPA Barcelona Attack Mossos d'Esquadra Police officers attend injured people after a van crashed into pedestrians in Las Ramblas, downtown Barcelona, Spain, 17 August 2017. According to initial reports a van crashed into a crowd in Barcelona's famous Placa Catalunya square at Las Ramblas area injuring several. Local media report the van driver ran away, metro and train stations were closed. The number of people injured and the reasons behind the incident are not yet known. Official sources have not confirmed that the incident is a terrorist attack. EPA Barcelona Attack Injured people react after a van crashed into pedestrians in Las Ramblas, downtown Barcelona, Spain, 17 August 2017. According to initial reports a van crashed into a crowd in Barcelona's famous Placa Catalunya square at Las Ramblas area injuring several. Local media report the van driver ran away, metro and train stations were closed. The number of people injured and the reasons behind the incident are not yet known. Official sources have not confirmed that the incident is a terrorist attack. EPA Barcelona Attack A police officer cordon off a street in Barcelona, Spain, Thursday, Aug. 17, 2017. Police in the northern Spanish city of Barcelona say a white van has jumped the sidewalk in the city's historic Las Ramblas district, injuring several people. AP Barcelona Attack TOPSHOT - Policemen check the area after towing away the van which ploughed into the crowd, killing at least 13 people and injuring around 100 others on the Rambla in Barcelona, on August 18, 2017. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least 13 people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack". The driver of a van that mowed into a packed street in Barcelona is still on the run, Spanish police said. / AFP PHOTO / Josep LAGOJOSEP LAGO/AFP/Getty Images AFP/Getty Images Barcelona Attack TOPSHOT - Armed policemen stand in a cordoned off area after a van ploughed into the crowd, injuring several persons on the Rambla in Barcelona on August 17, 2017. Police in Barcelona said they were dealing with a "terrorist attack" after a vehicle ploughed into a crowd of pedestrians on the city's famous Las Ramblas boulevard on August 17, 2017. Police were clearing the area after the incident, which has left a number of people injured. / AFP PHOTO / Josep LAGOJOSEP LAGO/AFP/Getty Images AFP/Getty Barcelona Attack A man displays flowers at the Canaletas fountain on the Rambla boulevard on August 18, 2017, a day after a van ploughed into the crowd, killing 13 persons and injuring over 100 on the Rambla in Barcelona. Drivers have ploughed on August 17, 2017 into pedestrians in two quick-succession, separate attacks in Barcelona and another popular Spanish seaside city, leaving 13 people dead and injuring more than 100 others. In the first incident, which was claimed by the Islamic State group, a white van sped into a street packed full of tourists in central Barcelona on Thursday afternoon, knocking people out of the way and killing 13 in a scene of chaos and horror. Some eight hours later in Cambrils, a city 120 kilometres south of Barcelona, an Audi A3 car rammed into pedestrians, injuring six civilians -- one of them critical -- and a police officer, authorities said. / AFP PHOTO / Josep LAGOJOSEP LAGO/AFP/Getty Images AFP/Getty Images Barcelona Attack TOPSHOT - The van who ploughed into the crowd, killing at least 13 people and injuring around 100 others is towed away from the Rambla in Barcelona on August 18, 2017. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least 13 people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack". The driver of a van that mowed into a packed street in Barcelona is still on the run, Spanish police said. / AFP PHOTO / Josep LAGOJOSEP LAGO/AFP/Getty Images AFP/Getty Barcelona Attack TOPSHOT - Forensic policemen arrive in the cordoned off area after a van ploughed into the crowd, killing 13 persons and injuring over 80 on the Rambla in Barcelona on August 17, 2017. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least 13 people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack". / AFP PHOTO / Josep LAGOJOSEP LAGO/AFP/Getty Images AFP/Getty Images Barcelona Attack TOPSHOT - A person is helped by Spanish policemen and two men after a van ploughed into the crowd, killing at least 13 people and injuring around 100 others on the Rambla in Barcelona on August 17, 2017. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least 13 people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack". The driver of a van that mowed into a packed street in Barcelona is still on the run, Spanish police said. / AFP PHOTO / Nicolas CARVALHO OCHOANICOLAS CARVALHO OCHOA/AFP/Getty Images AFP/Getty Images Barcelona Attack TOPSHOT - Policemen accompany clients of a store outside a cordoned off off area after a van ploughed into the crowd, killing 13 persons and injuring over 80 on the Rambla in Barcelona on August 17, 2017. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least 13 people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack". / AFP PHOTO / LLUIS GENELLUIS GENE/AFP/Getty Images AFP/Getty Images Barcelona Attack TOPSHOT - Forensic policemen arrive in the cordoned off area after a van ploughed into the crowd, killing at least 13 people and injuring around 100 others on the Rambla in Barcelona. A driver deliberately rammed a van into a crowd on Barcelona's most popular street on August 17, 2017 killing at least 13 people before fleeing to a nearby bar, police said. Officers in Spain's second-largest city said the ramming on Las Ramblas was a "terrorist attack". The driver of a van that mowed into a packed street in Barcelona is still on the run, Spanish police said. / AFP PHOTO / PAU BARRENAPAU BARRENA/AFP/Getty Images AFP/Getty Images

The Spanish Prime Minister Mariano Rajoy said terrorists will "never defeat united people". He is on his way to Barcelona to help coordinate efforts to reinforce security following the attack.

Ada Colau, the Mayor of Barcelona, also tweeted a moving message on Twitter saying her city was one of "peace".

"Thank you for the solidarity we have received from around the world. Barcelona is brave and united. Terror will never change that," she said.

Prime Minister Theresa May said her thoughts were with the victims of the "terrible attack" in Barcelona, adding: "The UK stands with Spain against terror."

Mayor of London Sadiq Khan also described the events as "a barbaric terrorist attack" and said London stood in solidarity with Barcelona.

He tweeted: "My thoughts are with the victims of this barbaric terrorist attack in the great city of Barcelona and with their brave emergency services.

"London stands with Barcelona against the evil of terrorism."

While full details of the incident were not immediately clear, since July 2016 vehicles have been used to ram into crowds in a series of militant attacks across Europe, killing well over 100 people in Nice, Berlin, London and Stockholm.

There have been no previous terror attacks claimed by Isis in Spain, where almost 200 people were killed by al-Qaeda inspired terrorists in the Madrid bombings in 2004.

Spanish police have arrested several suspected Isis supporters in recent years, including a suspected recruiter detained on Mallorca who was accused of inciting terror attacks.