Those three countries gave a statement on their investigation to the United Nations Security Council on Thursday. They said the sabotage was likely carried out by several teams of operatives who deployed experienced divers armed with limpet mines, which are are magnetic explosives usually attached to a ship's hull.
Read @UAEmissiontoUN@ksamissionun & @NorwayUN's joint statement on today's briefing to #UNSC members on the preliminary findings of the investigation into the coordinated attacks on four oil tankers that took place on the morning of 12 May 2019 off the port of Fujairah.
Iran, which lies some 60 miles from the UAE across the Gulf of Oman, has denied the allegations and has called for an independent investigation.
The backdrop to the sabotage attack last month is an atmosphere of rising tension between the U.S. and Iran. The administration of President Donald Trump has been taking a far more hawkish stance since coming into office, and U.S. officials have been warning about what they claim is the risk Iran could launch an attack.
Over the last month, the Trump administration announced that it was sending an aircraft carrier strike group and Air Force bombers to the Middle East, as well as Patriot missiles and additional troops.
The joint statement by the UAE, the Saudis and Norway describes a "sophisticated and coordinated operation carried out by an actor with significant operational capacity, most likely a state actor."
The attack was likely carried out by several teams of operatives navigating fast boats, slipping into UAE territorial waters and navigating through the busy anchorage off the port of Fujairah, the statement added.
Out of almost 200 vessels, these four tankers were deliberately selected and located using sophisticated intelligence capabilities, it said.
Once there, trained divers are believed to have been deployed, placing limpet mines at the water line of the ship's hulls so they were crippled but not sunk.