The US Treasury Department has sanctioned 21 ships, including a VLCC that collided with a Hafnia vessel, in the latest effort to put pressure on the dark fleet of tankers serving Iran.

The agency couched the move as a response to Iran’s 1 October missile attack on Israel and what it described as “nuclear escalations” by Tehran.

Treasury accused Iran of using petroleum revenue to fund its nuclear programme, develop advanced weapons and support proxy groups throughout the Middle East.