Listen to this articleDear 2 minutesThe audio version of this article is generated using AI-based technology. Pronunciation errors may occur. We are working with our partners to continually review and improve results. Iran said on Sunday it had attacked an unmanned US ship trying to enter the Strait of Hormuz, the latest salvo in a new outbreak of fighting between the two countries. The United States did not immediately confirm the alleged attack, which came a day after the U.S. military said forces attacked three Iranian oil tankers in response to a missile attack on Navy warships. The war began with the US and Israeli attacks on Iran on February 28. The attacks came about a week after fighting resumed. The United States and Iran resumed attacks last week, after a month of relative calm, and the Strait of Hormuz and Iranian communities along it were once again targeted. At least five people were killed earlier this week during a US bombing raid in southern Iran. The Trump administration appears to have taken a dual approach to the conflict, responding militarily to cross-strait attacks while also going after foreign financial institutions that handle Iran’s money. But Tehran’s new hardline senior leaders have signaled a willingness to go deeper after enduring decades of sanctions. Over the years, Iran has found ways to bypass sanctions, and now the US blockade, and obtain its oil. to buyers to help alleviate increasing economic pressures. That depends in part on a shadow fleet that transports its oil. Meanwhile, Iran’s nuclear program, the issue that contributed to the outbreak of war, was due to be addressed in negotiations that collapsed shortly after the United States and Iran signed a memorandum of understanding in mid-June. Diplomats say the United States, Britain, France and Germany are seeking to refer Iran to the U.N. Security Council for failure to meet its nuclear nonproliferation obligations. Instead, Tehran’s new influence is focused on the Strait of Hormuz, which is crucial to global shipments of oil and natural gas and was seen as an international waterway before the war began.