A Japanese tanker attacked in the Gulf of Oman last week was damaged by a limpet mine resembling Iranian mines, the US military in the Middle East said on Wednesday.
"The limpet mine that was used in the attack is distinguishable and it is also strikingly bearing a resemblance to Iranian mines that have already been publicly displayed in Iranian military parades," Commander Sean Kido of US Naval Forces Central Command said.
Kido told reporters in the UAE emirate of Fujairah that the US military has recovered "biometric information" of the assailants on the Japanese ship Kokuka Courageous including "hand and finger prints."
This information "can be used to build a criminal case," Kido told reporters.
Two oil tankers were partially damaged in an attack close to the Iranian coast on June 13, just outside the strategic Strait of Hormuz.
"Right now, there is an ongoing joint and combined investigation with our regional partners into the attacks on motor vessel Kokuka Courageous as well as motor vessel Front Altair," Kido said.
Kido said that based on NAVCENT assessment, Japanese tanker Kokuka Courageous was damaged by a limpet mine that was attached to the skin of the vessel.
"The limpet mine was placed above the water, and it does not appear that the intention was to sink the vessel," he said.
He reiterated the US claims that an Iranian Revolutionary Guard patrol vessel approached the Japanese ship and removed an unexploded limpet mine from the hull.
The two vessels have already been towed safely to the UAE coast.
Iran has categorically denied any hand in the attack, the second on oil tankers in the Gulf of Oman in a month.
On May 12, four tankers, two of them Saudi, were damaged in a "sabotage attack" off the coast of Fujairah.
Kido said a US military team quickly arrived on the Japanese ship on June 13 and was able to examine the site where the limpet mine was attached to the ship as well as the site where the damage occurred.
"The damage at the blasted hull is consistent with a limpet mine. It is not consistent with an external flying object striking the ship," Kido said.
In addition, the team was able to recover fragmentation caused by the detonation of the limpet mine, which was composed of aluminium as well as a composite material.