Germany has been rocked by an unprecedented series of four attacks in the last week leaving many dead and wounded.
The latest incident occurred in the Bavarian town of Ansbach, where a 27-year-old man blew himself up near the entrance to a music event, injuring 12 others.
It has added to a feeling of grief and insecurity in a country rocked by a spate of violent extreme acts.
The worst attack was on Friday when a teenager opened fire at a Munich shopping centre, killing nine and injuring dozens more.
Last Monday, a 17-year-old Afghan asylum seeker launched an axe and knife attack on passengers on a train in Wuerzburg, injuring five people.
Islamic State claimed responsibility for the attack in which the teenage axeman, Riaz Khan Ahmadzai, was shot dead by police.
Earlier in the month, a Syrian asylum seeker killed a woman with a machete and wounded two others outside a bus station in the south-western German city of Reutlingen before being arrested.