BARCELONA, Spain -- At least a dozen people were killed and more than 50 injured after a van rammed through crowds of people in the heart of Barcelona Thursday in an apparent terror attack.
Eyewitnesses reported panic and chaos as the van plowed through crowds in the renowned Las Ramblas avenue, which was teeming at the time with locals and tourists.
Two suspects have been arrested, Catalan police said. Police are treating the incident as a terror attack and have sealed off the area.
"We can confirm 13 dead and more than 50 injured," Joaquim Forn, the Catalan interior minister, told a news conference.
He had earlier given initial figures of one dead and 32 injured but warned that the toll was "bound to rise."
City officials ordered all public events to be canceled, while emergency services requested the closure of metro and train stations in the area.
Reports of the attack first emerged on social media at about 5 p.m. local time (11 a.m. ET). About two hours later, police confirmed that Spain had suffered a deadly attack.
It was the latest in a series of attacks in Europe in which vehicles have been used to mow down pedestrians in public spaces.
Catalan police said they were continuing to hunt for the perpetrators and that the force had activated its terror response protocols. Unconfirmed reports suggested the suspects may have been attempting to reach a getaway vehicle.
Local Spanish media earlier reported that two armed men had entered a restaurant.
As the incident unfolded, police told everyone in the vicinity of Plaça de Catalunya and Las Ramblas to remain indoors until told it was safe to go outside. Footage posted to social media by witnesses showed chaotic scenes with people lying in the street, apparently dead or injured.
Witness reports gunshots
One witness told local media the situation was "very tense" and that all surrounding shops were being evacuated. The witness said at least eight ambulances were at the scene. Emergency services said the area had been cordoned off and all public transportation stopped.
Another witness who was hiding in a shop nearby heard gunshots, according to state-run broadcaster TVE24. Another witness said he saw a van driving "around 80 kilometers" per hour, or 50 mph. He said "there is no doubt it was intentional," according to TVE24.
Tourist Susan McClean told CNN that she saw a "tidal wave" of people running away from Las Ramblas in the aftermath of the incident.
She ducked into a nearby shop and the shutters were pulled down while police sped toward the scene.
"There was clearly a lot of distress," she told CNN.
McClean said she returned to her hotel just a street away after leaving the shop.
Witness: 'Lot of distress'
The Catalonian regional government is convening an emergency meeting to discuss the incident, its vice-president, Oriol Junqueras, said in a tweet.
The Catalan emergency services urged people via Twitter to avoid going out or undertaking any other type of movement that is not "strictly necessary" to facilitate police operations.
Spanish Prime Minister Mariano Rajoy tweeted: "In contact with all administrations. Priority: tend to the injured in Las Ramblas and facilitate the work of security forces."
NATO Secretary General Jens Stoltenberg tweeted his condemnation of the attack. "My thoughts are with all those affected. We stand united in the fight against terrorism," he said.
London Mayor Sadiq Khan also tweeted his support, saying: "London stands with Barcelona against the evil of terrorism."
The US Consulate in Barcelona posted on Twitter: "We are aware of a reported incident at Las Ramblas in Barcelona. Please avoid the area and monitor local police @mossos for updates."
Las Ramblas is a predominantly pedestrianized street popular among tourists in Barcelona. Extending for about three-quarters of a mile through the center of the city, the tree-lined street is especially crowded in the summer, the height of tourist season.
The promenade passes by kiosks, flower sellers, pavement cafes and bars. It includes a number of the city's most popular sites.
Barcelona is consistently ranked one of the world's most visited cities.
Facebook has activated its Safety Check feature for Barcelona.
U.S. college basketball teams, coaches visiting Barcelona are all safe
Officials at Oregon State University, Arizona, Tulane and Clemson have confirmed that members of the basketball team traveling there are safe.
According to OSU Vice President Steve Clark, all coaches, members of the team and everyone else traveling with the squad were reported as safe. Clark noted that the attack happened near the hotel where the team is staying.
The Beavers is in Spain through August 25 on a tour where they are playing five exhibition games.
School officials are evaluating the team’s remaining travel schedule as allowed by safety officials in Spain.
Clark also noted that the entire OSU community extends its thoughts and prayers for all those injured and affected by this incident.
Developing story - more to come