Merkel broke off her summer holiday to address reporters in Berlin on Thursday and began by clarifying her stance on the issue of refugees in Germany.

It follows a chaotic week in which an asylum seeker purportedly from Afghanistan went on a stabbing rampage in Würzburg and an asylum applicant from Syria blew himself up outside a music festival in Ansbach. In Reutlingen a Syrian killed a woman and injured two others. In Munich, a German-Iranian killed nine people before killing himself.

"That two men who came to us as refugees are responsible for the deeds in Würzburg and Ansbach mocks the country which took them in, and I want to add that it does not matter to me at all whether these refugees came to us along with many other refugees before or after the fourth of September last year," Merkel said, referring to the large influx of asylum seekers who came to Germany in late summer 2015 after Merkel made it easier for those hoping to reach Germany to do so.

The chancellor also announced a range of nine policy alterations and plans in light of the attacks, including the bolstering of police forces where possible.

'We can do it'

Almost a year ago, Merkel gave her now-famous speech in which she told Germans "we can do it" (wir schaffen das) when it came to dealing with the challenges involved in taking in hundreds of thousands of people seeking refuge.

"Eleven months ago I said right here in this room that Germany is a strong country… we have achieved so much. We can do it."

"I didn't say 11 months ago that it would be a simple matter that we could easily solve," she said.

"But I am as convinced today as I was back then that we will manage our historic duty… And that's why we will also overcome the new challenge confronting us, which is called Islamist terror. We will introduce the correct measures and make clear that we want to give our citizens security and that we will master the task of integration," Merkel told reporters.

Chancellor to attend Munich memorial

Responding to questions about why she had not visited the scenes of the recent attacks, Merkel told journalists that she would attend a memorial ceremony scheduled for Sunday in Munich.

"That's a question that I obviously ask myself whenever something happens," she said. "A decision has to be taken on this each time and perhaps some members of the public have a different view to the way I decided to do things."

Merkel added that the Interior Minister, Thomas de Maiziere, went to Munich the day after the shooting there.

Merkel also declined to announce whether she would be standing for a fourth term as chancellor in elections scheduled for next year.