A fresh round of attacks by the U.S. on Sunday was the latest volley in a familiar pattern of back-and-forth strikes fueled by disputes over the Strait of Hormuz.

A fresh round of attacks by the U.S. on Sunday was the latest volley in a familiar pattern of back-and-forth strikes fueled by disputes over the Strait of Hormuz. The United States conducted a fresh round of strikes on Iranian targets on Sunday, a U.S. official said, extending a pattern of attacks between the two sides as their fragile cease-fire continued to unravel. Iranian state media reported explosions on an island in the Strait of Hormuz, an economically vital waterway at the center of a tug of war between the two countries. The U.S. official, who was not authorized to speak publicly, said the strikes were intended to degrade Iran’s ability to target commercial shipping in the strait, where an Iranian attack on a container ship on Saturday set off the latest exchanges of fire. The U.S. launched a barrage of attacks on Saturday, and Iran retaliated overnight by firing on U.S.-allied Persian Gulf Arab states. The back-and-forth attacks have played out over nearly a week, driven by a dispute over the Strait of Hormuz, where the U.S. has repeatedly accused Iran of attacking commercial vessels. Iran had not claimed responsibility for any attacks until Saturday, when it said it had fired on a Cypriot-flagged container ship that tried to use an unapproved route through the strait. Iran also declared the waterway, through which roughly 20 percent of the world’s oil supply passed before the war, closed. President Trump insisted on Sunday that the strait was open to shipping traffic, adding that the U.S. had “bombed the hell” out of Iran last night. The president also suggested that the two sides had been close to a deal over the weekend, before the attack on the ship, but offered no details. Iran has not said that it had agreed to any new deal, and Mr. Trump has often made unsubstantiated claims about the war. The White House did not immediately respond to a request for comment on Mr. Trump’s remarks. The Trump administration has said the truce struck last month would fully lift Tehran’s blockade of the strait. But Iran has insisted that all ships transiting the waterway travel through its territorial waters, as it seeks to use it as leverage in peace talks. Washington has demanded that Tehran abandon that claim and allow the free movement of commercial vessels. The U.S. official said the latest U.S. strikes, carried out early Sunday night local time, were aimed at Iranian missile and air defense systems, as well as small vessels operated by the Islamic Revolutionary Guards Corps.