In a Tweet, Wallström called it a "horrendous terror attack", adding "Those responsible must be pursued. Free speech must be defended."
Journalists in Sweden also spoke out against the attack against the weekly newspaper.
"It's an abominable deed and a terrorist deed aimed at free expression," says Jonas Nordling, the chair of the Swedish Union of Journalists, to news agency TT, adding that there is no place for discussions about whether it was right or wrong to publish material in this context.
"There is nothing that can make it right that people are mowed down, regardless of what they published," he says.
Johannes Klenell, who works at the Swedish satirical magazine Galago, tells news agency TT, "When something like this happens, it sets in motion tons of latent feelings of fear."
Klenell says, however, that what he is really worried about is the debate that may arise after this, which he believes will be exploited by the extreme right.
"The feeling is that this cannot lead to any positive discussion, whatsoever. It's just a big black hole," he says.