An undated photo published online by Iran's state-run English language TV network Press TV shows its news anchor, Marzieh Hashemi, born Melanie Franklin of New Orleans, whom the network said on Jan. 16, 2019, was detained in the U.S. Press TV

Tehran, Iran -- The English-language arm of Iran's state television broadcaster is reporting that its prominent American-born news anchor was arrested after flying into the United States. Press TV broke into its broadcast on Wednesday to report that Marzieh Hashemi, born Melanie Franklin of New Orleans, was arrested after arriving at St. Louis Lambert International Airport on Sunday.

The broadcaster, citing her family, said Hashemi was taken into FBI custody and brought to the Washington area. The report claimed Hashemi was being denied halal food, and was eating only crackers and other snack food.

A call to the FBI rang unanswered early on Wednesday morning. The bureau did not immediately respond to a written request for comment. Several local jails around Washington that house federal inmates also said they did not have her in custody.

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Iran, meanwhile, is holding 4 Americans

Hashemi's reported arrest comes amid heightened tensions between Iran and the U.S., with Iran holding at least four U.S. nationals on espionage charges, or no charges at all.

The family of U.S. Navy veteran Michael White revealed last week that White has been in captivity since last summer in Iran, and his mother said she has no idea about any possible charges against him.

White is the fourth American known to be held by Iran, and while CBS News has learned that Iran floated the idea of a prisoner exchange last year, State Department officials have not said whether the Trump administration is willing to negotiate. Contact between the two countries was cut off after President Trump exited the nuclear deal in May.

Sources have told CBS News that Iran is holding the Americans to try to extract concessions, such as those received in a deal reached with President Obama.

While the Trump administration offered to discuss prisoners last year, a senior administrative official said Iran turned that offer down, leaving the fate of the Americans unclear.