US-Iranian journalist believed to have been detained in Iran

News of Reza Valizadeh's imprisonment comes as Iran marks 45th anniversary of US embassy hostage crisis

An Iranian-American journalist who once worked for a US government-funded broadcaster is believed to have been detained by Iran for months, authorities have said, further raising the stakes as Tehran threatens to retaliate over an Israeli attack on the country.

The imprisonment of Reza Valizadeh, acknowledged to the Associated Press by the US State Department, came as Iran marked the 45th anniversary on Sunday of the US embassy takeover and hostage crisis. It also followed Iran's supreme leader, Ayatollah Ali Khamenei, threatening both Israel and the US the day before with a crushing response" as long-range B-52 bombers reached the Middle East in an attempt to deter Tehran.