Global oil prices rose for a fourth consecutive session Thursday, with U.S. diesel fuel nearing its highest level ever, as renewed strikes by the United States and Iran strained energy flows. "Escalation in the Middle East dashes any hope for a recovery in refined product flows, leaving markets tight," ING analysts wrote. Shipping in the Strait of Hormuz, which normally carries a fifth of the world's oil, has been mostly at a standstill. The U.S. Navy is blockading Iranian oil at sea while helping ships navigate the strait, allowing some flow. However, two tankers were attacked Monday off the coast of Oman, highlighting persistent risks.

The Trump administration has sought to downplay the disruption. U.S. energy secretary Chris Wright said oil passing through the strait reached prewar levels recently. Independent firms tracking shipping were skeptical. "Ship trackers have been estimating much more modest flows," ING analysts wrote. Over the 28 days ending Wednesday, a daily average of 7.5 million barrels of crude oil was exported from the Persian Gulf past the U.S. blockade, according to Tanker Trackers.com, with five million barrels daily through the Strait of Hormuz.

Jenny Gross and Aruni Soni contributed reporting.