There were no immediate reports of any Swedish nationals injured when vans drove into pedestrians in Barcelona and Cambrils, killing at least 14 and wounding some 100 others, but citizens from more than 30 countries were among the dead and wounded, reported The Local Spain.
Sweden's security services Säpo said they were ready to offer assistance if needed.
“Our thoughts go to those affected by the attacks in Spain and to our Spanish colleagues working extremely hard to investigate what has happened,” said Säpo head Anders Thornberg in a statement.
The attacks were carried out in a way similar to several other previous attacks in Europe and elsewhere, including Sweden where memories remain fresh of the Stockholm truck attack on April 7th earlier this year, where a man drove a stolen truck down a pedestrianized shopping street, killing five people.
“European security services face an historic challenge. We have a new normal situation in Europe when it comes to terrorism, and the threat to Sweden remains high,” said Thornberg.
“The security police are constantly working to face the threat by developing our operations and working together with other authorities in Sweden and internationally,” he added.
Säpo said the current terror threat level in Sweden remains unchanged at level three on a scale from one to five, where five is the highest. It has remained at this level since 2010, apart from a brief period between mid-November 2015 and March 2016, when it was temporarily raised to level four.
In a separate incident in Finland which also grabbed international headlines on Friday, police reinforced security at Helsinki airport and train stations after several people were stabbed in the centre of bilingual city Åbo (known as Turku in Finnish and Åbo in Swedish) in the afternoon. Police shot one suspect in the leg and detained him, reported Finnish news site Yle.
Finnish security police said at a press conference just after 6pm Stockholm time that they had no information yet about the attacker's background or motive. The following day they said they were investigating it as a terror attack.