Seven people are injured after attackers wearing fake bomb belts rammed civilians with a car in the seaside town of Cambrils.
It is the second attack in Spain in a matter of hours after tourists were hit in the busy Las Ramblas district of Barcelona.
The suspected suicide belts worn by the five attackers in Cambrils were fake, Catalonia's regional head Carles Puigdemont has said.
Mr Puigdemont was speaking to local radio.
Early on Friday morning police shot dead all five attackers who launched a vehicle attack in the Spanish coastal town, hours after an attack in Barcelona in which 13 people were killed.
Seven people, including a police officer, were injured during the Cambrils incident.
Barcelona's Las Ramblas promenade has been quietly reopened to the public.
Pedestrian were being allowed past police lines and back on the famous walkway on Friday morning, following the horrific attack that saw a van plough into holidaymakers and locals killing 13 people and wounding more than 100.
Barcelona is returning to its usual bustling self but the city centre is under tight surveillance, with armed police seen checking people's documents on Las Ramblas.
The street, which is nearly a mile long, is one of the city's most popular tourist attractions and is packed with cafes, restaurants, shops and stalls.
An Irish family of four are among those who have been caught up in the terror attack in Barcelona.
Their injuries are understood to be non life-threatening.
The mother and father are originally from the Philippines and are naturalised Irish citizens, while their two children were both born in Ireland, according to reports.
Ireland's Department of Foreign Affairs is assisting the family.
Irish President Michael D Higgins and Taoiseach Leo Varadkar were among the world leaders to condemn the attack, which killed 13 people and left more than 100 injured.
A third suspect has been arrested in connection with the Barcelona attack, the Catalonia interior ministry said.
The suspect was reportedly arrested in the northern Catalan town of Ripoll.
Police are already holding two people in custody over the attack. But they have yet to release their identities or announce any charges.
It is thought the driver of the van, which ploughed into the busy Las Ramblas area killed at least 13 and injuring 100, is still on the run.
Hours after the Barcelona attack, police shot dead five suspected terrorists who drove into people in the Spanish coastal town of Cambrils.
Seven people, including a police officer were injured.
Barcelona football club will pay tribute to the victims of their city's terror attack by wearing black armbands for their opening match of the season this weekend.
A minute's silence will also be held ahead of Barcelona's meeting with Real Betis at the Nou Camp on Sunday, as well as at matches across Spain.
Barcelona said in a statement:
The Spanish Football Federation also issued a statement calling for a minutes silence ahead of matches and expressing its "total condemnation" of the attack.
Meanwhile Lionel Messi, Luis Suarez and Neymar were among the football stars to express their shock and sadness at the events of Thursday.
The five suspected terrorists shot dead in Cambrils are linked to the van attack in Barcelona and an explosion at a house in Alcanar, Catalan police believe.
Seven people were injured in Cambrils, including a police officer, early on Friday when a group launched a vehicle attack similar to that which left 13 people dead and over 100 injured in Barcelona on Thursday.
One person was killed in an explosion on Wednesday night at the property in Alcanar, where gas cylinders were found.
