A van rammed into a crowd of people in the heart of Barcelona, causing a "number of deaths" and "many injuries," a Catalan police spokesman told CNN.
Police confirmed that the incident Thursday afternoon was a terror attack. The force has activated its terror response protocols.
The Catalonian government, citing Civil Protection, said one person was confirmed dead, seven were in serious condition in hospital and 17 were injured in the incident.
It occurred near the popular tourist area of Las Ramblas, which has been sealed off, according to a police spokesman.
Catalan police told everyone in the vicinity of Plaça de Catalunya to remain inside.
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.