The extremist Islamic State group has published a video in which a man pledges allegiance to IS and vows Germany's people "won't be able to sleep peacefully anymore." It appears to be the same as the one found by German investigators on the phone of man who blew himself, killing himself and wounding 15 people.

The IS-linked Aamaq news agency released the video early Tuesday. The man on the video, his face covered with a black scarf, threatens to make life intolerable and that "we will blow up your homes."

German authorities could not immediately be reached to confirm whether the video was the same as the one found on the cell phone of a 27-year-old Syrian who blew himself Sunday night in the Bavarian town of Ansbach.