The US is "confident" that Iran last week carried out an attack on a commercial oil tanker that killed two crew members, Secretary of State Antony Blinken said on Monday.

The top diplomat said the Biden administration carried out a review of the attack on the Mercer Street ship before making its formal assessment, saying Thursday's strike "follows a pattern of similar attacks by Iran, including past incidents with explosive drones."

"There is no justification for this attack on a peaceful vessel on a commercial mission in international waters," Blinken told reporters at the State Department. "Iran’s action is a direct threat to freedom of navigation and commerce. It took the lives of innocent sailors."

Iran has denied involvement in the strike, which occurred in the Indian Ocean on Thursday night while the vessel was en route from Tanzania to the United Arab Emirates.

Blinken said the US is "coordinating with our partners, and consulting with governments in the region" following the attack.

In recent months, many attacks on commercial vessels have been reported and linked to heightened tensions between Israel and Iran, with both nations accusing each other of responsibility. However, Thursday’s attack on the Mercer Street, a Liberian-flagged, Japanese-owned, and Israeli-operated tanker, has been described as the worst attack in several months.

The attack blasted a hole through the top of the tanker’s bridge, where the captain and crew were located.

Following the strike, the US aircraft carrier USS Ronald Reagan and the guided missile destroyer USS Mitscher escorted the Mercer Street to a nearby port./aa