Transcript for Deadly terror attack on streets of Barcelona

Good evening, and it's great to have you with us here on a very busy Thursday night, and we begin tonight with the horrific scene playing out in Barcelona in an historic shopping district where many tourists visit. A driver jumping the curb and his van barrelling through the crowd. Children believed to be among the victims tonight. So many images we cannot show here. The death toll, more than a dozen people dead, can the authorities warning that could go higher. More than 100 injured at this hour, and here's the van afterwards. It was going at speeds up to 50 miles per hour. One suspect dead, two in custody, and the urgent manhunt for others. ABC's James Longman leading us off from Barcelona. Reporter: Tonight, a trail of in the heart of Barcelona. The dead and injured lining the streets. First responders racing to the scene. Around 5:30 afternoon local time, police say this white van jumped onto a packed city sidewalk and began mowing down pedestrians. Swerving side to side at what witnesses guessed was 50 miles an hour, that speed, bringing chaos and carnage. I heard screams of people and when I looked up saw the white van and just knocking people over at high speed. Reporter: The van careening down this path in red for more than 1,000 feet. Before coming to a halt. We saw a lot of people running to the right of the restaurant, just running down the road or running from something and saw a couple of people hunched over a body on the floor. Reporter: At least 13 killed and about 100 injured. Crowds running in panic, fleeing this store. Come on. Come on. Just come with me. Reporter: Looking for a safe place to hide. Mayhem. Parents holding their children tight. Crowds streaming down main streets and back alleys. Many hiding in cafes. Somebody was screaming and everybody started to run, and there was screaming from behind, and everybody just ran forward. Reporter: You can make out the clothes discarded. Here's where the truck came plowing down the street. Historic las ramblas, popular with tourists -- shut down. Shops and resturnats closed as heavily armed police with guns drawn sweep the streets, searching for suspects. Police later announcing the arrest of two suspects, including this man who they say rented that white van this week, but said he was not the driver. They say a third suspect was killed. And James Longman joins us from the point where that van entered the pedestrian path, and James tonight, ISIS is claiming responsibility? Reporter: That's right, David. And just in the last few moments, we have heard the Spanish prime minister call this jihadist terrorism. Often with these ISIS attacks, there are other people involved and we have been watching groups of civilians being escorted by police out of here, because police want to make sure there are no other terrorists lying in wait. James Longman. Thank you. As James mentioned, one

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