A video showing the Syrian man who blew himself up in Ansbach, Germany, on Sunday evening pledging allegiance to the leader of so-called Islamic State has been found on his phone, says Bavaria's interior minister.

Joachim Hermann says two phones, multiple SIM cards and a laptop were found with the body of the 27-year-old asylum seeker or at his accommodation.

The man threatened a "revenge attack" on Germans in the video, he said.

Fifteen people were injured.

Bavarian authorities said that the bomb was constructed in such a way that it was clearly meant to kill as many people as possible.

Further bomb-making equipment was found at the asylum seeker accommodation where the man was living, including petrol, hydrogen peroxide and batteries, they added.

A detailed analysis of the content of the videos was ongoing, Mr Hermann said. "Some Salafist content was found," he said.