At first, the grenade attacks were mostly directed at cars and homes linked to criminals and their relatives — but from two years ago perpetrators began to target the nation’s “society and state”, an expert at Sweden’s National Police Department told SVT.

“One very worrying trend we’ve noticed is that from 2015, we started to see people throwing grenades at municipal buildings, police stations and police officers,” he said, lamenting how, as the number of attacks has increased, so has the number of people who have been injured.
And a very interesting statement:
According to Peter Hejdström, head of police investigation in Halmstad, the explosives — which are typically thrown by hand — are not a problem that is restricted to the big cities, as the widespread availability of grenades in Sweden means even rural areas have been affected.
'widespread availability of grenades'...  Apparently someone isn't- surprise!- obeying the law.

And you'll notice there's no mention of any possible connection to people of certain ethnicity or- well, hell, you know the rest.