Update: 1:04 p.m. EST— Eyewitness accounts are beginning to emerge after the vehicle-ramming attack.
Barcelona resident and American national Keith Fleming told the Associated Press that he heard a noise and went to his balcony to see what happened. He saw "women and children just running and they looked terrified."
"It's just kind of a tense situation....Clearly, people were scared," he said.
Update: 12:56 p.m. EST— Local radio station Cadena Ser Radio, citing police sources, says that at least 13 people have been killed in the vehicle-ramming attack. Police are yet to confirm this number, having only said that there are dead and injured as a result of the crash.
Spanish police have re-confirmed that they are treating the crash as an extremist attack.
The White House says that White House Chief of Staff John Kelly is keeping President Donald Trump informed of the situation in Barcelona.
Update: 12:46 p.m. EST— The Spanish government ordered train stations around Barcelona closed as the manhunt for the attacker continues.
The U.S. Consulate in Barcelona told Americans to remain clear of the Las Ramblas area as a security operation remains underway.
The British Ambassador to Spain Simon Manley said that the British Foreign Office is in touch with Spanish authorities, telling any British nationals in Barcelona to remain in a safe area.
Update: 12:36 p.m. EST— Two people are dead after the vehicle-ramming attack on Barcelona's Las Ramblas, a regional government source told AFP news agency.
"One of the attackers is holed up in a bar," said the source.
The number of injured remains unconfirmed but local media and eyewitnesses have said that the van hit dozens of people.
Catalan police said they have activated the protocols for the aftermath of an attack, but said that it could not confirm the motive behind the vehicle-ramming, even though they believe it to be intentional.
Update: 12:26 p.m. EST— Catalan police confirmed that there are dead and injured following the attack on Las Ramblas. They did not provide specific numbers.
They said that there is a manhunt underway for the driver of the van who plowed into dozens of civilians in Barcelona. Local media has said that the attacker is holed up in a bar.
Authorities are yet to confirm this but footage posted on Twitter showed armed police searching for the attacker in La Boqueria food market.

Pics not showing. Dunno