The call to the ship: "Forcing us to use force"

- Turn around or prepare to be boarded. If you do not comply with this blockade, we will use force. The entire US Navy is standing by to ensure that order is followed.

The warning came through a crackling radio noise on April 13 this year. It went out to ships located in the Persian Gulf and Gulf of Oman, according to the Wall Street Journal.

At 16:00 that day, the United States began its blockade of Iranian ports in the area, with the aim of forcing Iran to open the Strait of Hormuz. President Donald Trump warned that ships attempting to pass the blockade or come close to it would be "immediately eliminated." The approach, he said, was similar to that which had been used in attacks on drug boats in the Caribbean.

"It's fast and brutal," Trump wrote on social media.

Iran saw red. The blockade was called illegal and attacks were directed at commercial ships. The Sepah fleet, a special operations unit belonging to the Iranian Revolutionary Guard, also sent out its own messages to ships in the conflict zone.

- Inspection of all vessels in the Persian Gulf and the Gulf of Oman. This is the Sepah Fleet calling on channel 16. The Strait of Hormuz is still closed. We will open it on the order of our leader Imam Khamenei, not after the social media posts of some idiots, is heard in one of the Wall Street Journal audio recordings.

The newspaper has received about a dozen audio files that can be linked to both Iranian and American threats and attacks. There are also audio files that appear to describe how the US Navy helped evacuate crews from ships in distress.

One of the audio files has been linked to the attack on the Iranian-flagged crude oil tanker Hasna in early May. The tanker, which was not loaded with crude oil at the time, was fired upon by the giant US aircraft carrier USS Abraham Lincoln as it attempted to sail through the US blockade.

Ahead of the attack, several warnings were sent out to the crew of the Hasna, according to a statement from US Central Command.

- Again, I prepare to open fire on your stern. Leave the place now. This is a legal action and we have requested on several occasions that you follow our call. Your refusal forces us to use force. Clear the stern, the call is heard, according to the Wall Street Journal.

The shelling knocked out the Hasna's rudder and the oil tanker was forced to send out a distress call, revealing its position in the Gulf of Oman.

"Hasna is no longer on its way to Iran," the US Central Command wrote in its statement.