"This assessment is based on intelligence, the weapons used, the level of expertise needed to execute the operation, recent similar Iranian attacks on shipping, and the fact that no proxy group operating in the area has the resources and proficiency to act with such a high degree of sophistication," Pompeo said.
Crude oil prices spiked more than 4% after the attacks near the entrance to the Strait of Hormuz, a crucial shipping artery for Saudi Arabia and other Gulf energy producers, stoked fears such disruptions could impact oil flows from the Middle East. Prices later settled about 2% higher. Washington accused Tehran of being behind a similar attack on May 12 on four tankers in the same area.
Tensions between Iran and the United States, along with its allies including Saudi Arabia, have risen since US President Donald Trump pulled out of a deal last year between Iran and global powers that aimed to curb Tehran's nuclear ambitions. Iran has repeatedly warned it would block the Strait of Hormuz if it cannot sell its oil due to US sanctions.
No one claimed responsibility for the attacks. Analysts warned against jumping to conclusions about the culprit, saying it was conceivable that Iran might have carried them out but also that someone else might have done to discredit Tehran. Iranian Foreign Minister Mohammad Javad Zarif described the incidents as "suspicious" on Twitter and called for regional dialogue. Tehran has denied responsibility for the May 12 attacks.
A European security official said his nation was being very cautious in making judgments about the incident. "There are lots of moving parts and 'facts' at the moment, so my only advice would be treat things with extra caution," said the official, who spoke on condition of anonymity.
SHIPS ABANDONED
The crew of the Norwegian-owned Front Altair abandoned ship in the waters between Gulf Arab states and Iran after a blast that a source said might have been from a magnetic mine. The ship was ablaze, sending a huge plume of smoke into the air. The crew were picked up by a passing ship and handed to an Iranian rescue boat.
The second ship, the Japanese-owned Kokuka Courageous tanker whose crew were also picked up safely, was hit by a suspected torpedo, the firm that chartered the ship said. A person with knowledge of the matter said the attack did not use torpedoes, however. An unexploded device, believed to be a limpet mine, was spotted on the side of the Japanese tanker, a US official told Reuters, speaking on condition of anonymity. If confirmed, the next steps might be to either deactivate or detonate the device.