Turkish security forces detained 18 Daesh-linked suspects in counterterrorism operations in Istanbul, reports said Wednesday.

Counterterrorism squads from Istanbul Police raided 11 addresses in nine districts, upon finding out that the terrorists were planning to carry out attacks, Ihlas News Agency (IHA) reported.

Police confiscated digital materials and organizational documents in the raid, the report added.

The suspects were taken to the Istanbul Security Directorate after going through routine health checkups.

The terrorist group has been trying to establish a new formation in Turkey after receiving a heavy blow in Iraq and Syria. According to testimony by terrorists detained in previous operations in Adana province, Daesh had been attempting to kidnap judges, prosecutors and tourist groups as ransom in return for Daesh terrorists held in Iraq and Syria.

Turkey detained the so-called “Turkey emir” of Daesh, named Mahmut Özden, in August. He was planning to carry out an attack on Hagia Sophia Grand Mosque and target politicians, nongovernmental organization (NGO) heads and other prominent figures in Turkey, according to the official investigation.

Police deciphered encrypted messages of Daesh sent by the terrorist ringleaders in Syria and Iraq, with a wide range of instructions, including kidnapping tourist groups, prosecutors and deputies, attacking Incirlik Air Base in Adana and other plans.