Some 1,500 Turkish special forces, riot police and anti-terrorism units conducted the raids Sunday in the Gulsuyu and Gulensu neighborhoods of the Maltepe district in the Anatolian side of Istanbul, as well as in the Gazi neighborhood of the Sultangazi district on the European side, Today's Zaman reported Monday.
The raids were also conducted Monday morning.
The exact number of arrests was not reported.
The raids came after Interior Minister Muammer Guler called for a crackdown on illegal organizations, drug gangs and urban bandits after a group of armed people showed up Thursday for a memorial service for an anti-drug activist who was shot dead by suspected drug dealers.
The activist, Hasan Ferit Gedik, 21, was attending an anti-drug protest organized by the extreme-left Revolutionary People's Liberation Party/Front when he was shot. Four other people were injured in the shooting, Today's Zaman said.