Tehran on Saturday denounced as "sabotage" an attack on an Iranian vessel this week in the Mediterranean Sea.
The cargo ship, named Iran Shahr-e-Kord and owned by the Islamic Republic of Iran Shipping Lines group (IRISL), was en route from Iran to Europe on Wednesday when its hull was hit with "an explosive device", the group's spokesman Ali Ghiasian was quoted as saying on Friday.
Iran "received information confirming that the ship suffered a sabotage attack", foreign ministry spokesman Saeed Khatibzadeh said in a statement.
He confirmed the incident had "caused damage to the vessel", without elaborating on the extent or type of damage, and condemned the attack as "a flagrant violation of international law and maritime law".
Ghiasian called the incident a "terrorist action and an example of maritime piracy".
"A small fire started where the explosion had occurred, but it was quickly extinguished... and none of the crew were hurt," he said.
Khatibzadeh said Tehran was following up on the incident to "identify the perpetrators".
The ship was struck less than two weeks after Israel accused arch nemesis Iran of being behind an attack on an Israeli-owned ship in the Gulf of Oman, charges Tehran has strongly denied.
The United States blacklisted IRISL in mid-2020 over what the State Department described as the transportation of items related to Iran's missile and nuclear programme.
Former US president Donald Trump withdrew Washington from a landmark nuclear deal with Iran and world powers in 2018 and reimposed punishing sanctions on the Islamic republic.