Counterterror police units in Istanbul and Mersin conducted simultaneous operations against the far-left Revolutionary People's Liberation Party-Front (DHKP-C) on Thursday.
Istanbul police carried out the operation in several neighborhoods in the district of Sarıyer with the support of special operations teams and riot police units. While the number of suspects detained has not been revealed yet, they were reportedly sent to Istanbul Police Headquarters following medical examinations.
In the southern province of Mersin, counterterror units conducted the operation against DKHP-C-linked suspects who have been accused of arranging meetings for the organization's propaganda. Thirty-nine suspected were detained and sent to Mersin Police Headquarters.
On Wednesday, two terrorists attacked a police post with a stun grenade at the entrance of Dolmabahçe Palace, popular with tourists and home to the prime minister's Istanbul offices. Later, two suspects with automatic weapons were captured close to Taksim Square in connection with the attack.
One police officer was slightly injured in the attack.
Police said one of the detained suspects was previously arrested during operations into the DHKP-C in 2010 and 2013, whereas the other was arrested in 2010 and 2011 and they are searching for at least one more suspect.
Police also seized two grenades, a gun and other weapons, the Istanbul Governor's Office said in a statement on Wednesday.
Turkey has been in a heightened state of alert since launching a "synchronized war on terror" last month.