Berlin - Four attacks in a week — three of them carried out by asylum seekers — have left Germany on edge and Chancellor Angela Merkel’s policies of welcoming refugees under renewed criticism.

The unprecedented bloodshed began July 18, when a 17-year-old from Afghanistan wielding an ax attacked people on a train near Wuerzburg, wounding five people before he was shot to death by police. The Islamic State group claimed responsibility.

On Sunday, a 21-year-old Syrian used a machete to kill a 45-year-old Polish woman in the southern city of Reutlingen. Authorities said assailant and victim knew each other from working in the same restaurant, and the incident was not related to terrorism.

Also Sunday, a 27-year-old Syrian who was denied asylum detonated a backpack of explosives and shrapnel at the entrance to an outdoor music festival in Ansbach, killing himself and wounding 15 people. The Islamic State group claimed responsibility, and German security officials said a video on the attacker’s phone shows him pledging allegiance to the extremists.... Read More: VIN