The Strait of Hormuz has once again become a flashpoint in the standoff between Iran and the United States, adding to uncertainty in global energy markets. Tehran has announced attacks on a large number of ships attempting to pass through the strategic waterway, in what it says is retaliation for US attacks on Iranian oil tankers.

Iran's Revolutionary Guards said it had targeted two US warships, eight oil tankers and 10 other commercial vessels in the Gulf region. According to Tehran, the attacks came after the US bombed five Iranian tankers.

The Iranian Foreign Ministry described the US attacks as "a clear threat to regional and international peace and security", arguing that Iran has the right to respond in the context of "legitimate defense".

Passage through the Strait of Hormuz has been severely restricted since the outbreak of war in the Middle East. Tehran has announced that ships must obtain permission to pass through the maritime corridor, a demand that has been opposed by the United States and other countries in the region.

Iran has also warned of the creation of a "new no-go zone" near the waterway, which the Revolutionary Guards say will extend into parts of the Gulf of Oman and the Arabian Sea. Ships that enter without permission will face punitive measures, the Iranian warning said.

Meanwhile, the United Kingdom's Maritime Safety Information Office has reported several ships catching fire in various areas, without providing details on casualties or possible environmental consequences.