Chancellor Angela Merkel defended her refugee policy after violent attacks in Germany led to renewed criticism of her handling of the crisis and took a tough stand on security, saying asylum seekers who committed terror “mocked the country” sheltering them.

“It makes a mockery of the aid workers who have offered help and it makes a mockery of other refugees who truly are seeking safety from violence and war,” Merkel told reporters in Berlin on Thursday. The chancellor said she broke off her vacation to hold her summer press conference earlier than planned in light of the horrific assaults.

Merkel opened the annual event with a statement that laid out her plans to defend a German public shocked by the assaults that include lowering the barriers to deport refugees who don’t receive asylum and creating an “early warning system” to detect radicalization among migrants.

The 90-minute press conference was dominated by questions about the four assaults — a shooting spree, ax attack, suicide bombing and machete assault — that left 13 dead and sparked anxiety over terrorism.

The chancellor focused on two attacks committed by asylum seekers in Bavaria that officials say have a connection with Islamic State terrorism, in which one assailant blew himself up at a music festival and another was gunned down by police after he attacked people on a train with an ax. The assailants died in both cases after injuring others.

The bloodiest incident, a shooting spree in Munich on July 22 that killed 10 people including the assailant, was unrelated to international terror. That assailant, a teenager who was born and raised in Munich, harbored a fascination with mass shootings, including the murder of 77 people by right-wing terrorist Anders Behring Breivik in Norway in 2011, police have said.

Merkel warned that Islamic State-linked attacks along the lines of the “jarring and depressing” assaults in Paris and Nice could well take place on German soil and that her government would focus on doing everything imaginable to prevent such violence.

“We have to do whatever is humanly possible — and I want to do that in my work — to prevent any such attacks from taking place,” Merkel said.

While broad swathes of the political establishment and media have responded with unity in the wake of the attacks, some lawmakers in Merkel’s Christian Democratic-led bloc as well as politicians from the anti-immigrant Alternative for Germany party, or AfD, have revived criticism that Merkel has invited a security threat with her accommodating refugee policy.

Merkel rejected the criticism, repeating that Germany had a moral and legal obligation to take in those fleeing war and oppression. Her chancellorship has been beleaguered over the past year after more than 1 million asylum seekers made their way to the country in 2015, triggering public anxiety. She addressed her tag-phrase, “we can do this,” which she first used at last summer’s press conference.

“I didn’t say this as if it were something that we could do easily, otherwise I wouldn’t have said it,” Merkel said. “But I remain convinced that we will do it.”

(c) 2016, Bloomberg · Patrick Donahue, Arne Delfs