Despite protestations that it believes in freedom of speech following Monday's release of U.S.-born freelance journalist Roxana Saberi, Iran still holds 15 journalists and bloggers in custody, the Reuters international news service is reporting. Saberi, the North Dakota resident who reported from Tehran for the past five years, had been held since January on charges that included spying for the United States. U.S. officials had called the charges baseless and demanded her immediate release, so her release likely was a signal to President Barak Obama, who had personally called on Tehran to free Saveri, that Iran could approach moribund relations with the United States more constructively. Obama called Saveri's release a "humanitarian gesture," and administration spokesman Robert Gibbs said the president was "relieved." "We want to continue to stress that she was wrongly accused, but we welcome this humanitarian gesture," Gates said. Reporters Without Borders, the Paris-based international media watchdog group that previously called Saveri's arrest a warning to foreign journalists in Iran, said reporters and bloggers already in custody should use Saveri's release to challenge their own detentions. "The appeal court's decision to free her can be used as a legal precedent for other journalists currently detained in Iran," the organization said. Iran denies allegations that it is trying to stifle dissent, and says it welcomes constructive criticism and upholds free speech, Reuters said.