STOCKHOLM, Sweden — Sweden's intelligence service says it has increase security around the nation's main government buildings and the Norwegian embassy following Friday's blast and mass killing that shocked Norway.

SAPO Saturday said it is "closely following" the developments in Norway in the wake of the bomb blast that killed seven in the heart of Oslo, followed by a mass slaying of at least 84 youths attending a summer camp on a nearby island.

SAPO says it is keeping its terror threat alert level unchanged at "elevated," but that this "could come to change." Sweden raised it from low to elevated last October.

It says "police surveillance in the neighbourhoods surrounding the government and the prime minister's office, as well as the Norwegian embassy has been raised."