An ultra-leftist group linked to a string of armed attacks in Turkey has been the target of police raids in Istanbul and the southern province of Mersin.
More than 40 people in total were held in the early morning raids, police said, with the majority being detained in Mersin.
In Istanbul, the police operation took place in the Sariyer district of the city’s European side.
The People's Liberation Party-Front, or DHKP-C, has been targeted a day after police detained two suspects who attacked a security post near Istanbul's Dolmabahce Palace on Wednesday.
Police said the suspects are believed to be DHKP-C members; the organization is a designated terrorist group in Turkey.
It claimed responsibility for an Aug. 10 gun attack on the U.S. consulate in Istanbul.
Since July 24, well over 1,000 people have been arrested in a wave of counter-terrorism raids amid a growing number of attacks targeting Turkey's police and army.