There is evidence to suggest a Syrian migrant who blew himself up outside a music festival venue in southern Germany at the weekend had "direct contact" to an accomplice via the internet, Bavaria's top security official said Wednesday.
"The attacker evidently had direct contact in an online chat to someone who had significant influence over the terrorist plot," Bavarian Interior Minister Joachim Hermann said on the sidelines of a meeting of the state government.
The Islamic State extremist group has claimed responsibility for the attack, which saw a 27-year-old mentally disturbed Syrian asylum seeker injure 15 people in the Bavarian town of Ansbach by detonating a rucksack filled with explosives and shrapnel.
The terrorist group's weekly Al-Nabaa magazine late Tuesday released a report on the attacker, who has been identified as Mohammad Daleel. It claims the bombing was meticulously planned and that Daleel had been in constant contact with an Islamic State "soldier."
The Syrian attacker from Aleppo in northern Syria, who lost his wife and 6-month-old son in the war, suffered from depression and other psychological problems and had tried to commit suicide on two prior occasions.
A German psychologist tasked with assessing Daleel's mental health said in a report that the man was "capable of staging a suicide in a spectacular fashion," the BAMF agency for migration and refugees confirmed on Wednesday.
Daleel's bid for asylum in Germany was rejected in late 2014. He had been due for deportation to Bulgaria, the first EU country in which he registered, but that process was suspended due to his ailing mental health.
Authorities issued an order in March to reconsider Daleel's deportation to Bulgaria.
The Ansbach bombing was the fourth violent attack in Germany during the course of one week, with two of them claimed by the extremist group.
Three of the attacks were carried out by recent asylum seekers, which has reignited a debate in Germany about how to deal with criminal migrants. The country took in about 1.1 million new arrivals in 2015.
Chancellor Angela Merkel is cutting short a holiday to hold her annual press conference on Thursday, during which she is expected to frame a response to the violent incidents that have rocked the country.