Berlin's Senate interior department said it had outlawed Jama'atu Berlin, "a young and very radical jihad Salafist" association, also known as Tauhid Berlin, saying the group was advocating terrorist attacks.

Nineteen members of the association were the focus of Thursday's raids and the group had been under surveillance for two years, Berlin Interior Senator Andreas Geisel told a news conference.

A Senate statement said the group had propagated "a martyr cult", supported Islamic State ideology, rejected the German constitution and called for sharia as the sole legitimate law.

"(In the group), there are severe anti-Semites who are calling for the death of Jews," Berlin Interior Secretary Torsten Akmann said in a statement.

Akmann told the news conference the investigation was still ongoing.

Male and female members of the unregistered association met regularly in parks and private homes to teach and pray and spread the group's ideology over the internet and by distributing flyers in public spaces, the Senate statement said.

Several members also belonged to another Islamist group banned in 2017 which had contact with Anis Amri, a failed Tunisian asylum seeker with Islamist links who hijacked a truck and drove it into a Christmas market in Berlin in 2016, killing 12 people.

"The danger of Islamist terrorism remains high," Geisel said on Thursday. "Today's ban is another building block in the resolute fight against violent extremism."

Australian Associated Press