Barcelona terror strike: 'People were shouting and we heard a bang'
Islamic State's Amaq news agency said: "The perpetrators of the Barcelona attack are soldiers of the Islamic State and carried out the operation in response to calls for targeting coalition states."
A van ploughed into crowds in the Spanish city of Barcelona on Thursday killing 13 people and injuring at least hundred others.
Spanish Prime Minister Mariano Rajoy announced three days of official mourning for what he called a "jihadist attack."
Terror attack in Barcelona
Witnesses said the van zigzagged down one of Barcelona's busiest tourist avenues, Las Ramblas, mowing down pedestrians and leaving bodies strewn across the ground.
Mobile phone footage showed several bodies strewn along the Ramblas, some motionless. Paramedics and bystanders bent over them, treating them and trying to comfort those still conscious.
Around them, the boulevard was deserted, covered in rubbish and abandoned objects including hats, flip-flops, bags and a pram.
The incident took place at the height of the tourist season in Barcelona, which is one of Europe's top travel destinations with at least 11 million visitors a year.
Vehicles have been used to ram into crowds in a series of militant attacks across Europe since July 2016, killing well over 100 people in Nice, Berlin, London and Stockholm.
Barcelona attack: 13 killed at least 100 injured
Authorities in Vic, a small town outside Barcelona, said a van had been found there in connection with the attack. Spanish media had earlier reported that a second van had been hired as a getaway vehicle.
The attack was the deadliest in Spain since March 2004, when Islamist militants placed bombs on commuter trains in Madrid, killing 191 people and wounding more than 1,800.