BARCELONA, Spain — At least 13 people died and 100 people were injured after a van rammed into a crowd of people in a terror attack in the heart of Barcelona, a Catalan official said.
The attack occurred near the popular tourist area of Las Ramblas, which has been sealed off, according to a police spokesman.
The police confirmed that the incident Thursday afternoon was a terror attack and said the force has activated its terror response protocols.
The Islamic State group has claimed responsibility for the deadly attack.
A statement carried by the extremist group's media arm — the Aamaq news agency — says Thursday's attack was carried out by "soldiers of the Islamic State."
It says the attack was in response to IS calls for its followers to target countries participating in the coalition trying to drive the extremist group from Syria and Iraq.
Catalonia's regional president said there have been 2 arrests after the van attack.
The police force announced the first arrest on Twitter Thursday evening.
The tweet said: "There is nobody held up in any bar in the center of Barcelona. We have arrested one man and we are treating him as a terrorist."
The police force for Spain's Catalonia region says troopers have shot and killed a man who was in a car that hit two officers at a traffic blockade in Barcelona.
The Mossos d'Esquadra force did not indicate if the incident was related to the van attack in the city's Las Ramblas district on Thursday.
Meanwhile, the region's interior minister is calling on residents to remain indoors and avoid unnecessary travel while the investigation continues.
Catalan police told everyone in the vicinity of Plaça de Catalunya to remain inside. Footage posted to social media by witnesses showed chaotic scenes and people lying in the street.
Reuters reported that local emergency services have requested the closure of metro and train stations in the vicinity of the incident. Police told people to avoid the area.
A 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.
A 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.
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."
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.
The U.S. 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."
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.
Las Ramblas is a predominantly pedestrianized street popular among tourists in Barcelona. Located in 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.
Barcelona Mayor Ada Colau says a moment of silence will be held in the city's main square at noon Friday "to show that we are not scared and we are more united that ever."
The NYPD is "closely monitoring" the situation, according to a tweet from the department.
First Lady Melania Trump has tweeted about the incident, saying her thoughts and prayers are with Barcelona.