A makeshift memorial pays tribute to those who were killed in a terror attack in Barcelona, Spain, on Thursday, August 17. A van rammed into a crowd of people near the popular tourist area of Las Ramblas. Early the next morning, a group of five attackers drove into pedestrians in the Spanish town of Cambrils, about 75 miles south of Barcelona.

Two women cry at the street memorial in Barcelona on Friday, August 18.

A man embraces a police officer in Cambrils on August 18. Earlier in the day, officers had engaged in a shootout with five attackers who drove a car into several pedestrians. All five were shot dead by police, four of them by one officer, police said.

Pigeons fly over a Barcelona crowd that gathered for a minute of silence on August 18.

Spain's King Felipe VI joins other officials in observing a minute of silence in Barcelona's Plaça de Catalunya.

Police officers investigate a car in Cambrils.

The van that plowed into the crowd in Barcelona is towed away from Las Ramblas on August 18.

Police officers check the area after towing away the van.

Police accompany clients of a store outside a cordoned off-area of Barcelona. Las Ramblas is especially crowded in the summer, the height of tourist season. The promenade passes by kiosks, flower sellers, cafes and bars.

Police officers work at the scene in Cambrils.

Police check people's identities as they clear Las Ramblas on August 17.

People evacuate an area of Barcelona on August 17.

Medics and police tend to injured people near the scene of the attack in Barcelona.

A woman cries as she speaks on her phone in Barcelona on August 17.

People react after the incident in Barcelona.

A police officer asks people to move back in Barcelona.

An injured person is carried by police in Barcelona.

People flee the scene after the attack at Las Ramblas.

The Catalan emergency services urged people via Twitter to avoid going out or undertaking any other type of movement that is not "strictly necessary."