A Turkish court on Tuesday threw out an appeal against the detention of two editors from a top daily newspaper as a global media rights watchdog launched a major petition for their release. The higher Istanbul court rejected the appeal from lawyers for the Cumhuriyet daily's editor-in-chief Can Dundar and its Ankara bureau chief Erdem Gul who had been arrested on "spying" charges last week, the Dogan news agency reported. The case of the two journalists -- both hugely prominent figures on the Turkish media scene -- has amplified concerns about press freedom in Turkey under the rule of President Recep Tayyip Erdogan.