A new report released by U.S. Central Command on Friday says that last week's deadly attack on a shipping vessel in the Arabian Sea was conducted with an Iranian-made drone.
The oil tanker Mercer Street was targeted by three explosive unmanned aerial vehicle, or UAV, attacks between July 29 and July 30 while off the coast of Oman, U.S. Navy investigators found.
The first two attacks were unsuccessful, with the drones landing in the sea, according to the statement from Central Command.
The last attempt struck the vessel, killing the master of the ship, a Romanian citizen. A United Kingdom national who was part of the security detail also was killed.
The attack comes as tensions with Iran continue to grow over the increasingly beleaguered nuclear deal between the country and western nations. Iran has long used its position near critical shipping lanes to conduct asymmetric or grey-zone warfare as a way of exerting its influence on adversaries like Saudi Arabia, Israel and the United States.
The blast from the drone that hit the Mercer Street created a 6-foot diameter hole in the topside of the ship's pilot house and badly damaged the interior, the statement added.
The incident marks the first-known fatal attack after years of assaults on commercial shipping in the region. The attack led to threats of retaliation from Israel -- the tanker was managed by a firm owned by an Israeli billionaire -- as well as condemnation from the European Union and NATO.
U.S. Navy explosives experts were able to recover several pieces of the UAV that struck the ship, including a vertical stabilizer and internal components. The Central Command statement said that the parts were "nearly identical to previously-collected examples from Iranian one-way attack UAVs."
In presentation slides shared with the media, Capt. Bill Urban, a command spokesman, noted that "the use of Iranian designed and produced one way attack 'kamikaze' UAVs is a growing trend in the region."
Despite the evidence pointing to the drone's Iranian origins, Central Command did not explicitly say Iran conducted the attack.
In fact, Urban noted that Iranian drones "are actively used by Iran and their proxies against coalition forces in the region, to include targets in Saudi Arabia and Iraq."
Israeli and U.K. experts agreed with the findings that the drone was produced by Iran, according to the Central Command statement.
Secretary of Defense Lloyd Austin spoke with his Israeli counterpart about the incident on Friday, the Pentagon press secretary, John Kirby, told reporters. Kirby said the two men “expressed concern about Iran’s proliferation and employment of one-way attack UAVs across the region” and that “they agreed to work together alongside allies and partners in condemning Iran’s aggression that undermines freedom of navigation.”
The Defense Department also said it’s investigating reports of other merchant ships being hijacked by armed men near Iran’s coast in the last several days.
“We are aware of the reported incidents,” Army Lt. Col. Thomas Campbell, a defense department spokesman, told Military.com in an email.
“We are currently coordinating with our international partners on the next steps,” he added.
Explosive drones have been a threat in the region since at least 2015, when Kurdish fighters were killed by a small drone that blew up while they were taking it apart in Iraq.
In February, Marine Gen. Kenneth McKenzie Jr., the head of Central Command, said that small, weaponized drones pose the most concerning tactical development since the rise of the improvised explosive device in Iraq and Afghanistan.
-- Konstantin Toropin can be reached at email@example.com. Follow him on Twitter @ktoropin.