By Raphael Satter

But when the Tehran-based software developer logged on to Twitter he realized he was one of an unknown number of Iranian citizens who have received out-of-the-blue messages promoting the U.S. State Department’s recently announced effort to disrupt attempts to interfere with the American presidential election.

It is not clear who is behind the text messages, which were sent to the Iranian phone numbers overnight Thursday. The messages began surfacing online as bewildered recipients posted screenshots and photographs of the messages to Twitter and chat service Telegram.

Mohamed, who spoke with Reuters on condition that he be identified only by his first name, said he was among those who found the messages mystifying.

Written in Farsi, the messages say: “The United States pays up to $10 million for any information on foreign interference in American elections.” They carry a link to the U.S. Rewards for Justice Program, which offers cash bounties in return for information on threats to American national security.

On Wednesday, Secretary of State Mike Pompeo told reporters the U.S. was now offering up to $10 million “for information leading to the identification or location of any person who, acting at the direction or under the control of a foreign government, interferes with U.S. elections by engaging in certain criminal cyber activities.”

The State Department did not have an immediate comment on the Iranian text messages. The White House National Security Council did not immediately respond to a question about the texts.

Nariman Gharib, of London-based cybersecurity group Certfa, said he became aware of the messages when several recipients inside Iran approached him privately over Telegram early Thursday.

He said he was immediately troubled, saying the texts posed a safety risk to those inside the country.

“The moment you receive something like these kinds of messages from a government – we assume it’s the U.S. government – it’s going to be flagged by Iran,” he said.

He said that the United States had a range of options for communicating with Iranians, including online advertisements and Telegram channels.

“Direct communication with the Iranian people like this? Over a plain text message? It’s going to be dangerous.” (Reporting by Raphael Satter; Additional reporting by Humeyra Pamuk and Matt Spetalnick; Editing by Daniel Wallis)