A van has ploughed into pedestrians in Barcelona’s famous Las Ramblas tourist area, killing 13 people and injuring more than 100, BBC reports.
Spanish police have described it as a terror attack.
The attack began at 16:50 local time (14:50 GMT).
Witnesses described seeing a white van zig-zagging at speed along the pedestrianized area, deliberately targeting people, knocking many to the floor and sending others fleeing for cover in shops and cafes.
Catalan officials confirmed that 13 people had died. More than 100 were injured, 15 of them seriously.
The van was driven down Las Ramblas – a central boulevard that runs 1.2km (0.75 miles) through the centre of Barcelona. It is popular with tourists because of its market stalls, bars and restaurants.
Two people have been arrested in connection with the incident, one born in Morocco and one born in the Spanish enclave of Melilla, North Africa.
Police also released a picture of the man who allegedly rented the van. However, local media have since reported the man – named as Driss Oukabir – has handed himself in to police and told them his papers were stolen and used without his knowledge.
Police chief Josep Lluís Trapero said neither of the men arrested were the driver.
Spain’s national public broadcaster RTVE has also reported that the vehicle used was rented in the city.
The Islamic State militant group claimed the perpetrator was one of their “soldiers” in a release sent out via their self-styled news agency, Amaq.