An American-Iranian journalist who once worked for a US-funded broadcaster is believed to have been detained in Iran, according to his former employer and multiple press freedom groups. Reza Valizadeh was arrested in Tehran in September, a source close to ...

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

Amid U.S. warnings against a counterattack on Israel, Iran is sending a defiant diplomatic message: It is planning a complex response involving even more powerful warheads and other weapons, said Iranian and Arab officials briefed on the plans.

Rights groups said that Reza Valizadeh, an Iranian-American journalist, was recently arrested in Iran, although the State Department did not confirm that he was the person detained.