Among those detained is Dr. Kian Tajbakhsh, an Iranian American scholar, who was arrested on July 9 and his whereabouts remain unknown. Dr. Tajbakhsh, 47 had previously been one of four Iranian Americans detained in May 2007 on charges of endangering Iran’s national security, but denied the allegations and was released after about four months. Iranian authorities have neither confirmed nor denied Dr. Tajbakhsh’s recent arrest. We urge the Iranian authorities to disclose the whereabouts and conditions of Dr. Tajbakhsh and all other detainees, and to safeguard their rights under law.