Libreville- A Chadian journalist has been released without charge after four days in detention over the publication of an article criticising the country's president, he said on Thursday.Daniel Ngadjadoum, a contributor to Chadian newspaper Tribune Info, was released on Wednesday "on order of the prosecutor", he told AFP by phone from his nation's capital N'Djamena.The Paris-based Reporters Without Borders (RSF) media rights watchdog had condemned his detention in a statement on Wednesday.The group said he had been taken into custody by the National Security Agency (ANS) counter-espionage force, which is linked directly to President Idriss Deby's office."I was taken Sunday morning with my Bible in my hand, as I was coming out of church," Ngadjadoum said.ANS's director "asked me why I wrote an article headlined 'Idriss Deby, a deceitful poker player president'. I offered an explanation that convinced him, but he asked me to write a letter of apology", the journalist said."Under threat, I accepted."Ngadjadoum was eventually freed without charge.For 27 years, Deby has ruled Chad with an iron fist. The nation is a key ally of the West in the fight against jihadists.RSF lists Chad as the 127th nation out of 179 in its World Press Freedom Index, and describes the country as a "tough" place to be a journalist."Despite laws protecting media freedom, any criticism of the regime or its allies is immediately punished," the watchdog says on its website.