A Syrian man who tried unsuccessfully to claim asylum in Germany pledged allegiance to the Islamic State group and vowed the nation's people "won't be able to sleep peacefully anymore" in a cell phone video before blowing himself up outside a wine bar, wounding 15 people, authorities said Monday.
The assailant set off a backpack laden with explosives and shrapnel Sunday night after being refused entry to a crowded music festival in the Bavarian city of Ansbach because he didn't have a ticket.
It was the fourth attack to shake Germany in a week, and the second claimed by the Islamic State group. Three of the attacks were carried out by recent immigrants, rekindling concerns about Germany's ability to cope with the estimated 1 million migrants registered entering the country last year, an influx that has since dwindled as the flow of newcomers slowed.
Bavarian Interior Minister Joachim Herrmann said a laptop with extremist videos was found at the apartment of the suspect, a 27-year-old Syrian identified only as Mohammad D in line with German privacy laws. A video on his cellphone showed him declaring loyalty to the Islamic State group and announcing a "revenge act against Germans because they are standing in the way of Islam."
The suspect also declared Germans "won't be able to sleep peacefully anymore," Herrmann said. "I think after this video there's no doubt that the attack was a terror attack with an Islamist motivation."
In its claim of responsibility, the extremist group said the attack was carried out by "one of the soldiers of the Islamic State."
The IS-linked Aamaq news agency said the attacker acted in response to the extremist group's call to target countries of the U.S.-led coalition fighting it in Iraq and Syria. Germany is not involved in combat operations but has contributed reconnaissance aircraft to the effort.
After the IS connection surfaced, federal prosecutors in Karlsruhe, who investigate all suspected terrorism, took over the case saying they would seek to "determine if thus-far unknown accomplices or backers were involved in the crime."
The suspect came to Germany two years ago and applied for asylum in August 2014, Interior Minister Thomas de Maiziere said. It turned out that he had already registered in Bulgaria and later in Austria, so Germany rejected his request and ordered him deported to Bulgaria -- most recently on July 13.
Asylum-seekers are routinely deported to the first country where they registered if they don't follow proper procedures, even if they're considered to have a legitimate asylum claim.
De Maiziere said the man had attempted to take his own life twice before in Germany, and had been in psychiatric care.
Roman Fertinger, deputy police chief of nearby Nuremberg, said it was clear the suspect wanted to kill others, not just himself, in Sunday's attack.
"This was about destroying innocent bystanders," he said.
Sunday's attack culminated a week of violent assaults. On July 18, a 17-year-old Afghan asylum-seeker wounded five people with an ax before being killed by police near the Bavarian city of Wuerzburg in an attack that was also claimed by the Islamic State group.
On Friday, the 18-year-old son of Iranian immigrants went on a rampage at a Munich mall, killing nine people and wounding dozens. Authorities say he was undergoing psychiatric treatment and had no known links to terrorism.
And on Sunday, hours before the Ansbach attack, a Syrian man killed a woman with a knife in the southwestern city of Reutlingen before being captured by police in an incident authorities say was not believed linked to terrorism.
"Naturally people are concerned and are questioning whether they should change their routines," de Maiziere said. "We should not. ... We should continue to live our free lives."
Still, he said he had ordered an increased security presence at airports, train stations and elsewhere in the wake of the attacks.
"I understand that many people feel unsettled," he said.
The attack in Ansbach, a serene city of about 40,000 west of Nuremberg, came near the end of the closing night of a popular open-air music festival being attended by about 2,000 people.
In the wake of the Munich attack, city officials had ordered extra security and bag checks at the festival entrance, but the man never got that far because he didn't have a ticket, Mayor Carda Seidel said.
Fertinger said there likely would have been more casualties if the man had not been turned away. Four of the 15 victims suffered serious injuries.
Resident Claudia Frosch said she saw the suspect pacing in the street with a backpack, headphones and a cellphone before she entered a nearby cafe. Minutes later, "there was a very loud bang" and people started streaming into the building, covered in blood, she said.
"Everyone was shocked, nobody could help anyone, we didn't know what to do," she said.
In the aftermath, she said "obviously we now have more fear."
"I don't have anything against foreigners, asylum-seekers, I don't feel anything more against them," she said. "But obviously if I would see one with a backpack I will have more fear. I would be more cautious."
An Iranian asylum-seeker who lived in the same shelter as the assailant, said he had occasionally drunk coffee with the man and they had discussed religion. Alireza Khodadadi told The Associated Press that the suspect had insisted that the Islamic State group was not representative of Islam.
"He always said that, `No, I'm not with them, I don't like them' and such stuff. But I think he had some issues because, you know, he told lies so often without any reason, and I understand that he wants to be in the center of (attention), you know, he needed (attention)," Khodadadi said.
A team of 30 investigators was interviewing the man's acquaintances and examining evidence collected from his home.
The U.S. military has a facility in Ansbach, and following the attack it increased security there.
In Munich, meanwhile, authorities said Monday that a 16-year-old Afghan friend of the gunman who carried out the mall attack may have known of the assailant's plan in advance.
The teen was taken into custody late Sunday for questioning after police said they were able to retrieve a deleted chat between him and the suspect on the messaging app WhatsApp.
Police said the chat appeared to show that the 16-year-old met with the attacker immediately before the shooting started, and knew that he had a pistol.
Investigators say the two met last year as in-patients at a psychiatric ward. Both were being treated for online game addiction, among other things, they said.
Grieshaber and Rising reported from Berlin. Frank Jordans in Berlin, Hakan Kaplan in Ansbach and Bassem Mroue in Beirut contributed to this report.