BERLIN (AP) — German prosecutors say they’ve charged a German-Algerian dual national with supporting a terrorist organization over allegations that he aided Islamic State militants in Syria and Iraq.

The federal prosecutor’s office said Thursday that 32-year-old Samir K. was arrested Wednesday in Baden-Wuerttemberg after a series of searches in the southwestern state, as well as in Brandenburg, Hamburg and Lower Saxony.

Prosecutors say K., whose last name wasn’t released in line with privacy laws, organized email, Telegram, Twitter, WhatsApp and Facebook accounts under aliases for four IS militants between the years 2015 and 2017.

Using the accounts, prosecutors say, the militants from Germany were able to maintain “comparative communication” with other members of IS and distribute messages on the internet.

K. is being kept in custody as the investigation continues.