An Iranian woman enjoys a dip in the sea as vessels are seen in the Strait of Hormuz off the port city of Bandar Abbas, in southern Iran, Aug. 10. AFP-Yonhap

DUBAI — The U.S. and Yemen's Iran-aligned Houthis reported separate attacks on shipping on Tuesday as prospects for ending the Iran war appeared to dim, with Tehran saying the Strait of Hormuz would remain closed unless Washington accepts its conditions.

The attacks, in the Gulf of Oman leading to the strait and at the entrance to the Red Sea — both vital chokepoints for global oil supplies — come as the war shows no signs of ending despite repeated assertions from U.S. President Donald Trump of a deal being imminent. Oil prices gained and global shares retreated amid renewed pessimism about a quick end to the conflict.

Brent crude futures climbed 1.4 percent to settle at $88.91 per barrel and U.S. crude rose 1.3 percent to $83.20. At the southern end of the Red Sea, four crew members were killed in a suspected Houthi attack on a small cargo vessel in the Bab el-Mandeb Strait on Tuesday, Yemen's Transport Ministry said. Two Yemeni rescuers from an anti-Houthi military group were also killed, Yemen's Coast Guard said.

The fatalities aboard the Egyptian-owned Tihamah would be the first deaths on shipping by Yemen's Iran-aligned Houthis since the Iran war began. The Houthi-run news agency Saba reported that the group, which said last month it would impose a naval blockade on Saudi Arabia in the Red Sea, attacked a Saudi ship carrying military equipment in the Bab el-Mandeb Strait. It did not name the ship, and there was no immediate Saudi response to the report.