The city's police chief Celalettin Cerrah told the state-run Anatolian news agency: "To prevent possible terror incidents, police in civilian dress, along with uniformed police and dogs trained to (sniff out) explosives, have been assigned to the metro and tramway stations in Istanbul."
Cerrah did not specify that he had been given any particular warning as to whether there would be an attack or not on the rail systems, but said that it was a precautionary measure.
The Kurdistan Liberation Hawks (TAK) who are believed to behind the attacks in the Aegean seaside town on Sunday said they had warned the police about the device, however, officials had not confirmed that.
