Three tankers came under projectile attack in the Strait of Hormuz on Tuesday, the British military announced, in the latest assault targeting vessels transiting the waterway.
Hours after the attacks, the US Department of the Treasury announced it was revoking the general licence that had permitted the sale of Iranian oil.
The Treasury had issued the licence last month for a period of 60 days, lifting sanctions on Iranian oil as part of a temporary agreement to halt hostilities between the two countries. Treasury officials did not immediately respond to an Associated Press inquiry into the reasons for the revocation.
The new attacks in the strait were the most numerous in a single day since last April, according to the United Nations' International Maritime Organization. The fresh attacks threatened to choke the flow of traffic through the strait at a time when countries had been hoping to restore normal shipping movement and ease the global economic pressure caused by the war.
One of the tankers was sailing off the coast of Oman when it was targeted and caught fire, according to the United Kingdom Maritime Trade Operations centre. Iranian state television said the liquefied natural gas tanker had been attacked after ignoring warnings, but stopped short of directly claiming responsibility on behalf of Iran.
The other two vessels sustained some damage but none of those on board suffered injuries, and both continued on their way, according to the British authority.