The regional police for the Catalonia region said on Twitter early Friday that officers are in Cambrils, a seaside resort town about 62 miles from Barcelona.
They called on people in the town not to go out on the streets.
PHOTOS: Terror attack in Barcelona
Spain's public broadcaster, RTVE, is reporting that regional police troopers have killed four people and injured another.
The broadcaster says police suspected they were planning an attack in Cambrils just hours after a van swerved onto a pedestrian promenade in Barcelona, killing 13.
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