Iran said it had closed the Strait of Hormuz until further notice, in an official notice issued by a body identified as the Persian Gulf Strait Authority and circulated through state-linked channels on June 11.

A closure of the strait, the chokepoint through which roughly a fifth of the world's seaborne oil passes, would carry severe consequences for global energy markets, though the practical effect on shipping could not immediately be confirmed against tanker movements or independent maritime sources.

The notice said that in light of tensions it attributed to US forces in the region, and an overnight statement by Iran's armed forces, the strait would be closed until a further announcement. It asked holders of transit permits to be patient and to await subsequent guidance from the authority.

The announcement followed reports of US strikes against targets in Iran and a series of explosions across the Gulf, in an escalation that has drawn direct American military action against Iranian territory.

The strait links the Gulf to the Arabian Sea and the Indian Ocean and carries crude and condensate exports from Saudi Arabia, Iraq, Kuwait, Qatar, the United Arab Emirates and Iran itself. Its waters are territorial to Iran and Oman.

Enforcing a closure would require sustained military action and would expose tanker traffic across the wider Gulf to disruption.

Iran has periodically threatened to close the strait during past confrontations but has not previously sustained a full closure.