(VOVworld) – 4 people were killed and 15 injured when a truck crashed into a crowd in central Stockholm on Friday, the Swedish police reported, adding that they have arrested 2 suspects.

Tow trucks pull away the beer truck that crashed into the department store Ahlens after plowing down the Drottninggatan Street in central Stockholm, Sweden, April 8, 2017. (Photo: Maja Suslin/TT News Agency/ Reuters)

This is the latest attack after several attacks using public transportation in Europe. Swedish Prime Minister Stefan Lofven has asked functional forces to strengthen border security.

After the attack in Sweden, the police in major cities and airports of Norway have been equipped with weapons, while Finland has strengthened patrols in Helsinki.

The European Union on Friday expressed unity with Sweden. Head of the EU Commission (EC) Jean-Claude Juncker said any attack targeting an EU country means targeting all EU member countries. He said the Swedish government can expect support from the EC.