A total of 16 suspects were detained Tuesday in an operation against "migrant smuggling and human trafficking" in western Turkey's Aydın province, media sources reported.

The operation was launched by the anti-smuggling and organized crime units of the Aydın Gendarmerie Command, during which four motor boats, three dinghies, one fiber boat and 20 liters of fuel were seized.

After necessary procedures at the gendarmerie station, five suspects were referred to court. Four of the suspects were arrested by court decision, while one was released on condition of judicial control.

The remaining 11 suspects are still at the gendarmerie station, sources said.

Over the past years, thousands of people have made the short but dangerous journey across the Aegean in a bid to reach Greece, before continuing on to northern and western Europe.

Turkey's five Aegean provinces Çanakkale, Balıkesir, Izmir, Muğla and Aydın are the regions most frequently used by refugees leaving Turkey for the EU, which have also become a hub for migrant smugglers and human traffickers.

The EU-Turkey agreement reached on March 20, 2016, allows for the return of "irregular migrants" to Turkey from Greece, in exchange for Syrian refugees' relocation from Turkey to within the bloc.