TEHRAN – Iran has seized two Greek-flagged oil tankers in the Persian Gulf in a tit-for-tat move after Greece detained an Iranian-flagged oil tanker and transferred its cargo to the United States.

Nearly a month ago, Greece seized an Iranian-flagged oil tanker off its coast and then transferred its cargo to the United States. Reuters reported Thursday that the United States has confiscated Iranian oil held on a Russian-operated ship near Greece and will send the cargo to the United States aboard another vessel.

The Iranian-flagged ship, the Pegas, was among five vessels designated by Washington on Feb. 22 - two days before the start of the war in Ukraine for sanctions against Promsvyazbank, a bank viewed as critical to Russia's defense sector, according to Reuters.

The Greek move was quickly rejected by Iran and when it was announced that Iranian oil will be transferred to the U.S., Iran couldn't bear the Greek violation of international law any further.

First, Iran followed up on the issue diplomatically. The Greek chargé d'affaires was summoned to the Iranian Foreign Ministry to protest the move strongly. Iran condemned Greece’s surrender to U.S. pressure in this regard as unacceptable. The Greek diplomat was told that the confiscation of the cargo of the ship with Iran’s flag was an example of international piracy for which Athens and those who seized the ship illegally will be responsible.

Iran also summoned the Swiss chargé d'affaires as protector of U.S. interests to file a strong protest against Washington. Iran stressed to the Swiss diplomat the necessity of immediately ending the confiscation of the ship and its cargo.

Then Iran moved militarily to answer the Greek move. On Friday, the media office of the Islamic Revolution Guards Corps (IRGC) succinctly announced that the IRGC navy forces had detained two Greek oil tankers for violation of law in the Persian Gulf.

Iranian media said the seizure took place in response to the Greek move in detaining the Iranian oil tanker. Tasnim said the IRGC also issued warnings to other Greek ships sailing in the Persian Gulf. 

“There are still 17 Greek ships sailing in the Persian Gulf which will be possibly detained by the IRGC if Greece continues its mischief,” Tasnim warned.

Even though it made the first move, Greece accused Iran of “piracy” following the seizure of its ships. 

“These actions are tantamount to acts of piracy,” the Greek Foreign Ministry said in a statement, warning Greek citizens to avoid traveling to Iran.

The Greek move in transferring Iranian oil to the U.S. was a gross violation of international law and regulations as Greece isn’t obligated by U.S. unilateral sanctions on Iran. 

 “According to @GreeceMFA, it’s absolutely lawful to seize oil tankers if it’s done in application of U.S. extraterritorial law; but it amounts to ‘piracy’ and is ‘contrary to fundamental rules of international law and international navigation’ if it’s done as a countermeasure by an aggrieved state!” Reza Nasri, an expert on international law, wrote on his Twitter account. 

Ali Reza Salimi, a member of the Iranian parliament’s presiding board, also said Iran has a right to detain the Greek ships because Greece violated international law. “The Greeks should be held responsible for their measures, and that detention of the two Greek ships is part of Iran’s right,” he said, according to ICANA.