Three American hikers who were arrested in Iran this summer after straying across its border with Iraq have been charged with spying, an Iranian state news agency reported on Monday.

The Tehran prosecutor told Iran’s official IRNA news agency that Iranian officials were pursuing espionage charges against the Americans, who were detained in late July after trekking through the Kurdistan region of Iraq and toward the Iranian border.

News of the charges drew a quick rebuke from Secretary of State Hillary Clinton, who reiterated calls for the Iranians to release the hikers, Shane M Bauer of Emeryville, California; Joshua F Fattal of Cottage Grove, Oregon; and Sarah E Shourd of Oakland, California.