Tunisia’s main journalism union said anti-terrorism police detained a radio reporter on Friday for refusing to reveal his sources on a story about militants, describing the decision as a new attempt to undermine press freedom. Amira Mohamed, an official from the National Syndicate of Tunisian Journalists, said “the reporter from Mosaique FM was held for questioning after broadcasting a story about authorities breaking up a militant cell.” The police’s National Unit for Investigation of Terrorist Crimes did not immediately respond to phone calls seeking comment. “What is happening is a shame, t…