The British man who was killed in the Sweden lorry attack has been named as 41-year-old Chris Bevington.
Two Swedes and a Belgian national were also killed when a hijacked lorry ploughed into pedestrians in Stockholm on Friday.
Rakhmat Akilov, a 39-year-old man from Uzbekistan, has been arrested on suspicion of "terrorist crimes through murder".
European Commission President Jean-Claude Juncker has said "an attack on any of our [the EU] Member States is an attack on us all", following the lorry crash in Stockholm which has left at least three people dead.
Mr Juncker said: "Our thoughts are with the people of Sweden following the tragic events in Stockholm today.
"On behalf of the European Commission, I would like to send my sincere condolences to the families of the victims and to salute the courageous work of the first responders who arrived so quickly on the scene.
"One of Europe's most vibrant and colourful cities appears to have been struck by those wishing it – and our very way of life – harm.
"We stand shoulder to shoulder in solidarity with the people of Sweden and the Swedish authorities can count on the European Commission to support them in any which way we can.
"An attack on any of our Member States is an attack on us all."
The main suspect in the Stockholm lorry attack has admitted to carrying out a terror crime, his defence lawyer said.
The Ahlens department store in Stockholm apologised "for a bad decision" in promoting the offer.
The British man who was killed in the Stockholm lorry attack has been named as Chris Bevington.