Turkish security forces detained four suspects over their links to the Daesh terrorist organization in a counterterrorism operation in northwestern Sakarya province on Thursday.

The Counterterrorism Branch of the Sakarya Security Directorate raided a house located in the Mithatpaşa neighborhood of Adapazarı district with the support of Special Operation Units under an investigation launched by the Sakarya Chief Public Prosecutor's Office.

The detained suspects were reported to be Iraqi nationals.

Turkish security forces have been involved in a long-running campaign to rid Turkey of Daesh terrorists. The terrorist group is blamed for a string of terror attacks in Turkey that killed dozens of people over the past three years in Istanbul and Ankara as well as cities in the southeast.

Military operations in Syria and Iraq led to a rapid decline in Daesh territories and the number of its militants. Turkey helped the Syrian moderate opposition, the Free Syrian Army (FSA), to regain control of a number of Daesh-controlled towns in an operation in 2016.

Foreigners looking to join Daesh in Syria have mostly attempted to use Turkey as their crossing point. Turkey has taken significant measures against foreign Daesh members and has urged Western countries for intelligence cooperation.

According to official figures, some 2,000 people were arrested and 7,000 others deported in operations against Daesh in Turkey, while around 70,000 people were denied entry to Turkey over their suspected links to the terrorist group.

Security forces have also foiled at least 10 attack plots. Figures show that some 18,500 suspects are currently being monitored for links to the terrorist group after being identified at airports upon arrival.