Oil prices extended their gains on Monday as reciprocal U.S. and Iranian strikes on vessels in and around the Strait of Hormuz raised concerns about a prolonged disruption to Middle East supplies. Brent crude futures rose 52 cents, or 0.54%, to $96.80 a barrel by 2354 GMT, while U.S. West Texas Intermediate crude gained 66 cents, or 0.72%, to $92.14. Brent advanced 7.8% last week and WTI nearly 10% after the United States and Iran resumed attacks, reducing oil flows through the Strait of Hormuz, through which a fifth of the world's oil supply used to transit. U.S. forces struck three Iranian oil tankers on Saturday, including one off Kharg Island near Iran's key oil-export hub, the U.S. Central Command said. The navy of Iran's Islamic Revolutionary Guard Corps (IRGC) said it targeted three tankers using unauthorized routes through the strait and three additional U.S. vessels elsewhere. Marisks described the attacks as a major escalation in the maritime conflict, saying commercial tankers were being used as instruments of reciprocal economic pressure. Kpler data showed that an average of 10 commodity ships crossed the strait daily during the previous 10 days, the lowest level since May. Iran will announce a restricted zone outside the strait in the coming days, Mohsen Rezaei, the secretary of Iran's Supreme National Security Council, said on Sunday, according to state media. OPEC+ left its October oil-output policy unchanged as members still need to agree on new quotas before determining subsequent production steps. ANZ analysts said a prolonged standoff marked by calibrated U.S. and Iranian military action appeared the most likely scenario, potentially delaying the full recovery of Middle East supply. They expect exports to remain constrained through the rest of 2026, followed by a gradual reopening late in the fourth quarter of 2026; a return to pre-war throughput is not expected until late in the first quarter or early in the second quarter of 2027.