Spanish police say they have killed five suspected terrorists in the town of Cambrils to stop a vehicle attack, after an earlier one in Barcelona.
Thirteen people died and dozens were hurt when a van hit crowds in the Las Ramblas area of Barcelona on Thursday. The driver fled and is still at large.
Spain’s PM Mariano Rajoy described it a “jihadist attack”, which so-called Islamic State said it had carried out.
Mr Rajoy has announced three days of national mourning and a minute’s silence will be held later on Friday.
The authorities are now also linking the attacks in Barcelona and Cambrils with an explosion at a house on Wednesday evening in the town of Alcanar that left one person dead.
Police chief Josep Lluis Trapero said it appeared the residents at the Alcanar house had been “preparing an explosive device”.
In Cambrils, seven people, including a police officer, were wounded when a car was driven into them early on Friday, Catalan emergency services said. One person is in a critical condition.
Spanish media reported that the attackers’ vehicle overturned and when the men got out they were quickly fired upon by police.
A series of controlled explosions was then carried out.
Police say the situation in Cambrils – a popular seaside resort to the south-west of Barcelona – is now under control.
Meanwhile police are continuing to search for the driver of the van used in the Barcelona attack, who fled on foot. He is believed to be the sole attacker there.
Tourists and locals fled when the rented vehicle sped down Las Ramblas in the centre of the city, mowing down people.
Witnesses said the van deliberately targeted people, weaving from side to side as it drove down the boulevard.