I need to point out that it's been stated that ISIS called for people to attack in the same way this 'person' did. So yes, it is completely safe to assume it is an islamic terror attack.
Also, islamophobia isn't there without a reason. Do I need to point out that almost all of the attacks happening currently (not decades, not centuries ago, right now) are being done under the name of islam? No, not all muslims are terrorists, but it's fair for people to be a little worried about the religion in the current state of affairs.