Three suspects were remanded into custody in northwestern Turkey after five others were arrested for allegedly helping PKK and Gülenist Terror Group (FETÖ) members flee to Greece.

The move came after police squads combating migrant smuggling and human trafficking raided previously spotted locations in Edirne province, bordering Greece. Aside from the arrests, police seized five inflatable boats, a boat engine, life jackets and rifles during the operation, the sources said.

FETÖ and its U.S.-based leader Fetullah Gülen orchestrated the defeated coup on July 15, 2016, which left 251 people killed and nearly 2,200 injured. The PKK also remains a major terror threat for Turkey, conducting a violent campaign of more than three decades that has killed thousands.

As more members of FETÖ attempt to escape to Greece, a police probe found that a senior member of the group sent instructions to others on how to make it into the country neighboring Turkey. The "guidelines" sent to Gülenists were discovered on several members detained by the security forces.

Using an illegal migrants' route, FETÖ suspects fleeing a crackdown in the wake of their 2016 coup attempt continue to try to secretly enter Europe. Some mingle with illegal migrants from other countries, while others join forces with members of other terrorist groups, like the PKK, to cross into Greece. Tight border patrols along the border in the northwestern province of Edirne often thwart the attempts. Last month, security forces stopped 30 FETÖ-linked suspects trying to cross into Greece.