German leaders voiced their shame over resurgent anti-Semitism on Friday, one year after a deadly attack targeting Jews in the city of Halle, as a tribute to the victims was defaced with swastikas.

Two people were killed in the attack on October 9, 2019 during Yom Kippur, the holiest day in the Jewish calendar, in one of the worst acts of anti-Semitic violence in Germany's post-war history.

A heavily armed man tried to storm the synagogue, but when the door failed to break down he shot dead a female passer-by and a man at a kebab shop instead.

"I feel deep sadness. But even a year later I still feel shame and anger," President Frank-Walter Steinmeier said at a commemoration to mark a year since the attack.

The synagogue door that withstood an anti-Semitic attacker's bullets has been turned into a memorial in Halle
The synagogue door that withstood an anti-Semitic attacker's bullets has been turned into a memorial in Halle AFP / Ronny Hartmann

No one should stand by and watch anti-Semitism "in the underground, in a caf?, in the schoolyard, on the street, on the internet", Steinmeier added.

"Everyone must stand up when the human dignity of others is violated," he said.

At 12.01 pm (1001 GMT), the time the attacker fired his first shot at the door of the synagogue, all the church bells in Halle rang for two minutes.

In the afternoon, a memorial was unveiled incorporating the old door of the synagogue.

German President Frank-Walter Steinmeier laid a wreath at the synagogue as part of the memorial ceremony
German President Frank-Walter Steinmeier laid a wreath at the synagogue as part of the memorial ceremony AFP / Ronny Hartmann

The attack shocked Germany and led leaders to vow "never again".

But a year on from the assault, graffiti tributes to the victims sprayed across the city were defaced with swastikas.

A plaque commemorates the two victims of the 2019 shooting outside the Halle synagogue
A plaque commemorates the two victims of the 2019 shooting outside the Halle synagogue AFP / Ronny Hartmann

A left-wing group called Antifa Halle had sprayed stencil images with the names of the two victims in various locations on Sunday night, according to a report in the Bild daily.

But some of the images with the inscription "Never forget -- Kevin and Jana" were smeared with red swastikas on Thursday night, the report said.

An investigation has been launched and work has begun to remove the swastikas, police told AFP.

The Antifa Halle group said in a statement sent to media that its graffiti was intended to draw attention to the fact that nothing has changed a year on from the attack, Bild reported.

Anti-Semitic crimes have risen steadily in Germany in recent years, with 2,032 offences recorded in 2019, up 13 percent on the previous year.

They have sparked soul-searching in Germany, which has placed a huge emphasis on atoning for the murder of six million European Jews by Adolf Hitler's Nazi regime during World War II.

Just this week, a Jewish student was attacked outside a synagogue in Hamburg in a case that police are treating as attempted murder with anti-Semitic intent, condemned by Chancellor Angela Merkel as a "disgrace".

A neo-Nazi suspect, 28-year-old Stephan Balliet, is currently on trial for the Halle attack and has told the court it was "not a mistake".

Foreign Minister Heiko Maas also voiced his regret on Friday at anti-Semitism in Germany.

"One cannot say that the problem has left us -- and the fact that we have to protect Jewish institutions in 2020 is actually a state of affairs that is not acceptable," Maas told the RTL broadcaster.

Germany