Brent oil prices rose on Tuesday, after reports said that the U.S. had carried out fresh attacks against Iran, offsetting hopes that a deal to reopen the Strait of Hormuz was close. 

Brent crude futures for July, the global oil benchmark, gained 3.4% to $99.45 a barrel by 05:23 ET (09:23 GMT), after having slid nearly 3% on Monday. Prior to the war, Brent was exchanging hands at around $70 a barrel.

U.S. West Texas Intermediate crude futures fell by 3.9 to $92.85 a barrel. WTI futures did not settle on Monday on account of a U.S. market holiday.  

The U.S. military carried out what it described as “defensive” strikes in southern Iran, sinking two Islamic Revolutionary Guard Corps vessels trying to lay mines in the Strait of Hormuz. The attacks sparked a retaliation from Tehran, which fired missiles at U.S. planes. American attacks then hit missile launchers near Bandar Abbas, the Wall Street Journal reported, citing a U.S. official.

The renewed military action largely tempered hopes for an imminent deal to end the nearly three-month conflict. Earlier reports had suggested the U.S. and Iran had agreed in principle on a framework deal to end the war and reopen the Strait of Hormuz, a vital waterway for a fifth of the world’s oil that has been all but shuttered since the start of the joint U.S. and Israeli assault on Iran in late February.

U.S. Secretary of State Marco Rubio said after the latest round of U.S. strikes that the Strait of Hormuz was going to open “one way or the other.” But he also noted that negotiating a deal with Iran could “take a few days.”

“Since the weekend, the real hope is that the days may also be numbered for the war in Iran […], with momentum building since the start of the weekend that a deal could be in the works,” analysts at Deutsche Bank said in a morning briefing note, highlighting that Brent is now trading well below Friday’s close.

“Net net, optimism is still elevated that an agreement can be made to end the war. We have been here before, of course, but it has felt for some time that the move towards peace has been three steps forward and one or two back,” the Deutsche Bank analysts said.