German police on Tuesday arrested five men suspected of links to the Islamic State group, who allegedly sought to recruit fighters for the jihadists.

‘The five accused formed a pan-regional Salafist-jihadist network, with the accused Ahmad Abdulaziz Abdullah A. taking on the leading role,’ said a statement from the prosecutors' office.

The 32-year-old Iraqi leader of the group, who also goes by the alias Abu Walaa, is one of the most influential Islamist preachers in Germany, said Ralf Jaeger, interior minister of the western state of North Rhine-Westphalia.

‘The aim of the network led by him is to send people to IS in Syria,’ said federal prosecutors.

Turkish national Hasan C. and German-Serb Boban S. were allegedly tasked with teaching the recruits Arabic as well as indoctrinating them with Islamist content.

While the group's leader had the authority to approve and organise any departures to Syria, he allegedly left the actual implementation of the plans to the two other men detained Tuesday, German national Mahmoud O. and Cameroonian Ahmed F.Y.

The five men were arrested in the northern state of Lower Saxony and in North Rhine-Westphalia.

At least one young man and his family has been sent by the network to join IS in Syria, prosecutors added.

Burkhard Freier, who leads North Rhine-Westphalia's domestic security service, said the group had ‘no concrete plans of attack.’

The probe will focus on two elements, he said: ‘first on the radicalisation of young people and secondly, which is something that the investigations must still prove -- was there people smuggling, was there ideological conditioning and ideological preparation for a departure to Syria.’

Hasan C. was in contact with two teenagers with Islamist backgrounds who were arrested over an explosion that wounded three people at a Sikh temple in the western city of Essen in April, said Freier.

According to figures released in May by German intelligence services, 820 jihadists have left Germany for Syria and Iraq.

Almost a third have returned and 140 were killed while abroad, while around 420 are still in Syria or Iraq.

Germany has so far been spared large-scale jihadist attacks.

But it was shaken by two assaults claimed by IS and carried out by asylum seekers -- an axe rampage on a train in Wuerzburg that injured five, and a suicide bombing in Ansbach in which 15 people were hurt.

Police said last month they had foiled an alleged plot by a Syrian refugee to bomb one of Berlin's airports.