Iran's state maritime body said on Saturday the crew of two Greek tankers seized by Revolutionary Guards on Friday have not been detained, were in good health and on board their vessels, the semi-official Tasnim news agency reported.
"The crew of the two Greek tankers have not been arrested, and all crew members ... are in good health and are being protected, and provided with necessary services while on board, in accordance with international law," Iran's Ports and Maritime Organization said in a statement carried by Tasnim.
Iranian forces seized two Greek tankers in the Gulf on Friday, shortly after Tehran warned it would take "punitive action" against Athens over the confiscation of Iranian oil by the United States from a tanker held off the Greek coast.
The two vessels were stopped over unspecified "maritime violations", the body said.
Greece said on Friday an Iranian navy helicopter landed on Greek-flagged vessel Delta Poseidon in international waters, and took the crew hostage. It said a similar incident took place on another Greek-flagged vessel near Iran, without naming the ship. Athens said both actions violated international law.
Greek authorities last month impounded the Iranian-flagged Pegas off Greece due to European Union sanctions. The United States later confiscated the Iranian oil cargo held onboard, Reuters reported on Thursday.
The Pegas and its Russian crew were later released, but the seizure inflamed tensions as Iran and world powers seek to revive a 2015 nuclear deal.
Separately, Nour News, affiliated to an Iranian state security body, said: "Iran will not remain passive in the face of any threat to its interests, and testing Iran's will is a strategic error that will entail heavy costs for the United States and its entourage."
Iran's Foreign Ministry spokesperson Saeed Khatibzadeh tweeted: "Our ties must not be hampered by deeply shortsighted miscalculations, including highway robbery on the command of a 3rd party."
In 2019, Iran seized a British tanker near the Strait of Hormuz for alleged violations two weeks after British forces detained an Iranian tanker near Gibraltar, accusing it of shipping oil to Syria in violation of European Union sanctions. Both vessels were later released.