Turkish security forces detained 18 suspects in Istanbul and Izmir for alleged links to the Daesh terror group, police sources said on Thursday.

Counter-terrorism squads carried out simultaneous raids in 14 addresses in Istanbul's nine districts to apprehend 11 wanted suspects who were allegedly plotting terror attacks, a source, who asked not to be named due to restrictions on speaking to the media, told Anadolu Agency.

During the raids, police apprehended eight foreign nationals. The operation remains ongoing to nab the remaining three.

Meanwhile in western province of Izmir, police units backed by the National Intelligence Agency (MIT) detained 10 suspects for links to Daesh.

The operation was launched by Izmir Chief Public Prosecutor's office on the grounds that the suspects recruit new militants to the terrorist group and provide financial support.

Simultaneous raids were conducted in four districts.

Security forces have been involved in a long-running campaign to rid Turkey of Daesh terrorists and sever their recruitment, support and financial links with militants fighting on the ground in Syria and Iraq.

More than 300 people have lost their lives in Daesh-claimed attacks in Turkey, where the terror group has targeted civilians and security in suicide bomb, rocket, and gun attacks.

Turkish military is also actively fighting with the terrorist group on the ground in Syria, killing or apprehending thousands.