In the attack in Ansbach, a town about 209 kilometers (130 miles) north of Munich, the Bavarian interior minister, Joachim Hermann, said the killer had been refused asylum a year ago but had not been deported. He said a terror motive could not be ruled out, as the backpack he carried contained pieces of metal.
The attacker had attempted to enter an open-air music festival in the town, but had been denied entry. He then set off his explosive device in a backpack, which contained metal shards to cause maximum damage, police said. There were conflicting reports over whether the attack had been inspired or planned by the Islamic State.
Initially, the local prosecutor’s office said there was no evidence of a link to IS. But later Monday morning, Mr. Hermann seemed to qualify his earlier comments, saying: “My personal opinion is that I think it could be possible that this was a real Islamic terror suicide attack.”
Mr. Hermann said the bomber had tried to commit suicide twice before and had received psychiatric treatment in Ansbach, a town of about 40,000 people.
At a press conference early Monday morning in Germany, Mr. Hermann said: “It is terrible that someone abuses the opportunity to find protection here in such a way. I am appalled by that.”
The music festival was called off and more than 2,000 people left the area. Ansbach’s old city has been sealed off by authorities and residents weren’t able to return to their homes.
The attack came shortly after police arrested a 21-year-old Syrian refugee Sunday after he killed a pregnant woman with a machete. The man fatally attacked the woman, and injured two others, during an argument near the bus station.
In the Munich mass shooting, police on Saturday said they found no IS connections to the attacker, but did find literature about police tactics in recent mass shootings.
Over the weekend, police arrested a 16-year-old friend of the killer on suspicion of being an accomplice. Police said the Iranian shooter had had a history of social problems, had been bullied in school, and was being treated by mental health officials.
The Munich killer apparently planned his attack meticulously over a year to coincide with the fifth anniversary of a shooting in Norway, in which a neo-Nazi killed 77 people, most of them teenagers or young adults, during a political party retreat on an island called Utoya near Oslo.
In the train attack last Monday near Würzburg in Bavaria, police said they found a home-made IS flag in the home of the 17-year-old train attacker, but no evidence that IS was involved.