German police raided four apartments and two businesses in Berlin on Thursday morning looking for alleged Islamists suspected of "planning a grave subversive violent crime", according to a police statement. They seized computers, mobile phones and other material.
"We know that at least one of the men received military training" in an ISIS terror camp, Berlin police spokesman spokesman Stefan Redlich told NBC News.
A total of 450 police officers were deployed in the operation.
German press agency DPA reported that the tapped telephone conversations of suspects led to a suspicion that they might have been identifying possible targets in Berlin, including tourist attractions, for a terrorist attack in the German capital.
It was noted that during the raids a woman, who had been wanted in connection to another case, was also arrested.
Police said "investigations show that he has been trained militarily in Syria".
"Our understanding is that the four men accused could have planned to carry out an attack together", Mr Steltner said.
Police officers tracked down two other suspects but did not arrest them.
No weapons were found in the operation, Redlich said, but mass circulation daily Bild said that investigators were searching for explosives.
News reports said it was another Algerian national, who was held in custody for having counterfeit identity documents.
One of the suspects was also being sought by Algerian officials for ISIS membership, officials said. Abdelhamid Abaaoud, the mastermind of the November 2015 Paris attacks, was a Molenbeek resident.
Germany, which is part of the worldwide coalition operating in Syria and Iraq, has not been targeted by Islamist terrorists to date.
Since the November Paris attacks in which IS gunmen and suicide bombers attacked Paris nightspots, killing 130 people, German authorities have issued terrorism alerts on several occasions. Authorities cancelled a friendly worldwide soccer match in Hanover last year and closed stations in Munich at New Year due to security concerns.
Rand Paul drops out of White House race
Ayotte, New Hampshire's top Republican elected official, says the decision "undermines" the state's role in the primary process. And we certainly deserve a Senator whose focus is on Kentucky, not one focused on planning his next run for President.
