NEW DELHI: A failed Syrian asylum seeker has blown himself up and injured 12 other people with a backpack bomb near a festival in Ansbach, Germany. Seperately, a 21-year-old Syrian refugee was arrested on Sunday after killing a pregnant woman with a machete in Reutlingen.

Although neither of the above attacks appear to be linked to terrorism, they will go a long way in fuelling public unease over Chancellor Angela Merkel's open-door refugee policy that has seen over a million migrants enter Germany over the past year.

This is more so as the attacks follow a shooting rampage in Munich that killed nine people on Friday. The gunman was of Iranian origin, but a search of his apartment reveals no links to terrorism and instead paints a picture of a man obsessed with mass murder.

More significantly, the attacks follow a knife rampage on a train claimed by so-called Islamic State last Monday, where an axe-wielding Afghan asylum seeker teenager was shot dead after injuring five people in Wuerzburg.

In neighbouring France, a Tunisian man drove a truck into Bastille Day holiday crowds in the French city of Nice killing 84 people on July 14. The Islamic State claimed the attack, which in turn fueled tensions across Europe.

It is worth reiterating that barring the Wuerzburg attack, the attacks in Germany in the last week have no link to terror. The Wuerzburg attack too has a limited link, if any, as a black flag was found on the attacker and a YouTube video showed him seemingly pledging allegiance to the Islamic State. However, there is no evidence of communication or coordination between the attacker and the militant group, making the attack a “lone wolf” style attack where the attacker was inspired but not commanded or guided by the Islamic State.

In reference to the Munich attack, what emerges as we peer into the life and thoughts of the 18 year old attacker is the picture of a deranged lone gunman obsessed with mass killings. Seven of his victims were teenagers themselves, lured to their deaths via a hacked Facebook account on what was the fifth anniversary of twin attacks by Norwegian mass murderer Anders Breivik which killed 77 people.

The attacks over the weekend, similarly, seem to have no link to terrorism. The 27 year old asylum seeker who blew himself up seemed to be mentally disturbed; he was known to have tried to take his own life twice and had spent time in a psychiatric clinic.

The Syrian man entered Germany two years ago and had his asylum claim rejected a year ago, Bavarian Interior Minister Joachim Herrmann said. "We don't know if this man planned on suicide or if he had the intention of killing others," he said. The minister added that he was "incensed" by the attack and that it demonstrated the need to "strengthen controls on those we have living in our country".

Seperately, police have described the attack on a pregnant woman with a machete as a “crime of passion,” as victim and the 21 year old Syrian attacker both worked at the same Turkish fast-food restaurant. Police said the attack happened after an argument developed between the man and the 45-year-old Polish woman.

Police added that the man arrested had been involved in previous incidents where he had caused injury, but gave no further details.

Despite the absence of links to terror, the attacks will fuel an anti-refugee sentiment in Germany and across Europe. A leader of the anti-immigrant Alternative for Germany (AfD)posted a Twitter message after the Munich shooting that said, "Merkel's unity party: thank you for the terror in Germany and Europe!" The message was later deleted.