Unknown attackers hurled a hand grenade against the leftist Turkish daily Jumhuriet, which is located in a populated area in the European part of Istanbul, the Turkish Ihlas news agency said Saturday quoting a Turkish police official. "However, the grenade failed to explode because there was no pressure on the detonating device," the official said. He added that a large number of policemen were rushed to the scene of the incident."Experts in explosives immediately succeeded in defusing the bomb," the official said. He added that an investigation was launched together with a search for the assailants after securing their pictures from the daily paper's outside monitoring cameras.