Säpo is monitoring the situation following the incident in Brussels.
– It is terribly serious, spokesman Adam Samara told TT.
– But exactly what we are doing and what the dialog with our partners looks like, we cannot go into details at the moment.
The alleged perpetrator claimed allegiance to the terrorist Sunni extremist movement IS and said in a video clip shared on social media that he wanted to "avenge Muslims". Belgian prosecutors say the man is targeting Swedes in particular. The victims are said to have been wearing Swedish soccer jerseys.
However, the terrorist threat level in Sweden is not affected by the act, according to Säpo. Less than two months ago, the head of the Security Service decided to raise the terrorist threat level in Sweden from an elevated threat to a high threat, from a three to a four on a five-point scale.
Säpo then stated that the decision to raise the terror threat level was not due to a single incident, but should be seen as a consequence of "a gradual deterioration of the threat picture against Sweden", including in the wake of the Koran burnings.
– The background to the decision was precisely a development we have seen over time, where Sweden has become an increasingly prioritized target for violent Islamist extremism, Samara said.
Update: 10:13
The police in Brussels have shot dead the suspect. Abdesalem Lassoued, 45, was shot in a café in the Schaerbeek neighbourhood.