Prime Minister Recep Tayyip Erdogan said the killing of Armenian-Turkish journalist Hrant Dink was an attack against Turkey's unity and vowed to catch those responsible. Erdogan said two suspects had been arrested, but that the full details of the killing were not yet known. "Once again, dark hands have chosen our country and spilled blood in Istanbul to achieve their dark goals," Erdogan said at a news conference. "We are investigating all aspects of this crime," he said. Erdogan said he had assigned top officials from the Justice Ministry to the case and that they were on their way to Istanbul from the capital, Ankara.