One of the perpetrators of the Barcelona attack was killed after an exchange of fire with the police, according to Spanish local reports.
The incident occurred on the outskirts of the city, Spanish newspaper La Fangardia reported.
Police earlier confirmed they had arrested a man linked to the attack.
Spanish authorities said a second man was arrested in Manliu, 50 miles north of Barcelona, Sky News reported.
It was not clear how many attackers had taken part in the incident, which killed at least 13 people.