Iran has called on the US to release one of its journalists who, it says, was illegally arrested by the FBI while making a family visit.
American-born reporter Marzieh Hashemi was reportedly taken into custody upon landing in St Louis on Sunday and subjected to "inhumane" conditions.
Ms Hashemi's reported arrest came after Iran detained at least four Americans, some on espionage charges.
The FBI has not confirmed the broadcaster's arrest.
Ms Hashemi, 59, is reportedly now in Washington DC following her arrest at St Louis Lambert International Airport.
US media have been unable to verify Ms Hashemi's situation with the FBI or any local jails. The FBI did not immediately return a BBC request for comment.
Iranian foreign ministry spokesman Bahram Qasemi said Iran condemned the treatment of Ms Hashemi.
Ms Hashemi's employer, the English-language state broadcaster Press TV, issued a lengthy statement expressing "strong protest" at Ms Hashemi's situation.
According to the outlet, Ms Hashemi told her family in a phone call on Tuesday she had been "subjected to violent and abusive treatment from the very onset".
She said she did not know why she had been detained. The authorities allegedly forced her to remove her hijab and allowed her to wear only a short-sleeved shirt, going against her Muslim beliefs.
BDST: 2158 HRS, JAN 16, 2019