A spokesman for Turkey's president says that a prosecutor has ordered internet providers to block social networking sites, including Twitter and YouTube.
The request stems from postings of photos that show militant marxists pointing a gun at a prosecutor who died last week in a shootout between police and the marxists who were holding him hostage.
"This has to do with the publishing of the prosecutor's picture. What happened in the aftermath (of the prosecutor's killing) is as grim as the incident itself," presidential spokesman Ibrahim Kalin said.
Government officials have blasted Turkish media for posting the images.
It was not immediately clear how the order was being carried out, but the government-run Anadolu Agency quoted the Union of Internet Providers as confirming that access to Twitter and YouTube has been blocked.
Last year, Turkey closed down access to YouTube and Twitter after leaked recordings suggested corruption by people close to President Recep Tayyip Erdogan.