The building of the German Federal Supreme Court (Bundesgerichtshof) is seen in Karlsruhe, Germany, Sept. 13, 2016.
The building of the German Federal Supreme Court (Bundesgerichtshof) is seen in Karlsruhe, Germany, Sept. 13, 2016.

German authorities have arrested three men suspected of membership in Islamic State, who allegedly were sent into the country by the terrorist group last year.

Speaking to reporters Tuesday in Berlin, Interior Minister Thomas de Maiziere said the three men, who arrived in Germany using the Balkan route, were arrested in the northern part of the country.

It appeared that they used the same smugglers and received phony Syrian passports made in the same workshop as some of those involved in the Paris attacks, de Maiziere said.

They allegedly arrived in Germany in mid-November and had been under observation, but there were no indications of concrete plans for attacks at this stage, he said, adding that they may have been a sleeper cell.

"Three people have been arrested," said de Maiziere. "They are being accused of being members of a terrorist organization. According to the current state of information, the investigations by the federal criminal police office [BKA] indicate connections to the perpetrators of the attacks in Paris in November 2015. All three came to Germany via the Balkan route. At this stage there are no indications of concrete plans for attacks, but there is the suspicion that the arrested [people] have been sent to Germany by the so-called Islamic State [group] in November 2015. They may have been advised to wait for instructions by the Islamic State [group] in Germany, and could therefore have been a sleeper cell."

More than 200 police commandos took part in the pre-dawn raids that led to the detentions.

A statement issued by federal prosecutors partially identified the suspects as Mahir al-H., 17, Ibrahim M., 18, and Mohamed A., 26.

Six locations in two German states were searched Tuesday, the statement said, and “extensive material” was seized as evidence.

About a million migrants arrived in Germany last year and their presence has become an issue of concern after a recent series of violent attacks, three of which were carried out by asylum seekers. Of those, two were claimed by Islamic State.