The Pentagon said the photos, taken from a Navy helicopter, show Iranian forces removing an unexploded mine from the side of the Japanese-owned Kokuka Courageous.
Other photos show a large hole on the side of the Courageous, above the water line, that officials say appears to have been caused by another mine.
The Pentagon released the photos to bolster its claim that Iran was responsible for the attacks.
“Iran is responsible for the attack based on video evidence and the resources and proficiency needed to quickly remove the unexploded limpet mine,” the US military’s Central Command said in a statement.
Iran insists the US has no hard evidence about its alleged involvement in the 13 June attacks on two ships in the Strait of Hormuz.
Foreign Secretary Jeremy Hunt has said the UK’s own assessment was that Iran was behind the planting of limpet mines on the tankers.
Despite British and US intelligence findings, Germany and others insisted on Monday it needed a clearer picture before wading into a row which could have serious implications in the Middle East.
It comes as Iran said it will pull out of the world’s nuclear non-proliferation treaty if the EU fails to save another deal struck in 2015 on its nuclear programme.
Mojtaba Zolnour said: “There is not much time left until the end of the 60 days ultimatum given by Iran to the Europeans to save the (2015) deal,” he said.
“After that Iran will suspend implementation of the non-proliferation treaty.”
The 2015 nuclear deal between Iran, the US, the UK, France, China, Russia and Germany, called the JCPOA, reduced Iran’s stockpile of uranium by 98% to 300kg (660lbs), and said that quantity must not be exceeded until 2031.
However, the US unilaterally pulled out of the agreement last year and reimposed sanctions.
Source: Sky News