Counterterrorism police in the western city of İzmir Tuesday detained six suspects, including three Syrian nationals, for membership in Daesh. The operation in the country's third-largest city comes on the eve of Turkey's national Victory Day, an event marked with nationwide celebrations.

Authorities said "digital materials and documents" with Daesh propaganda were found in the suspects' possession.

Daesh views Turkey to be an infidel state like almost all Muslim-majority countries it has declared to be enemies. It has become one of the most active terrorist groups in Turkey over a span of just three years and is blamed for a string of attacks in the country, ranging from suicide bombings to gun attacks. On New Year's Eve, a lone Daesh gunman stormed a popular nightclub in Istanbul where he killed 39 people during celebrations. The gunman was apprehended a few weeks later.Since the terrorist group's emergence, Turkey has detained over 5,000 suspects and last year launched Operation Euphrates Shield to back Syrian opposition groups fighting Daesh in Syria. The country has deported over 5,000 Daesh suspects and prohibited the entry of over 53,000 terrorist suspects so far. Two weeks ago, two foreigners with links to Daesh were captured in Istanbul's Beylikdüzü district. Authorities said the two suspects, whose nationalities were not disclosed, illegally entered Turkey and were planning "sensational" attacks. Police found a shotgun, two pistols and a large cache of ammunition in their possession.