The 13 suspected members of a jihadist group arrested in raids across Europe were allegedly recruiting foreign fighters to be sent to Iraq and Syria.
The raids in Finland, Germany, Italy, Norway, Switzerland and the UK targeted Rawti Shax, which seeks to establish a caliphate in Iraq's Kurdistan region.
Among those arrested was the group's imprisoned leader, Mullah Krekar.
Italian police said the group was also planning attacks with the aim of securing his release by Norway.
Krekar, an Iraqi Kurd, is serving an 18-month sentence for making threats and encouraging others to commit criminal acts.
Thursday's raids saw suspected leaders and members of Rawti Shax arrested in Italy, Norway and the UK, and premises searched in Germany, Finland and Switzerland.