Oil prices jumped in premarket U.S. trade on Monday after Iranian media reported that two missiles had struck a U.S. warship in the Strait of Hormuz, heightening fears of further escalation in the region.

The move in oil price was later tempered after a senior U.S. official denied the claim, according to Axios journalist Barak Ravid.

Earlier today, oil prices were also pressured by the Organization of Petroleum Exporting Countries and allies voting to increase its production quotas, in the face of increasing supply disruptions due to the U.S.-Israel war on Iran. 

Elsewhere, Ukrainian drone attacks on a Russian port and other energy infrastructure also pushed up concerns over supply disruptions. 

Brent oil futures for July rose 3.3% to $111.79 a barrel by 06:47 ET (10:47 GMT), while West Texas Intermediate crude futures was up 2.9% to $104.87 a barrel. Brent crude rose to as much as $114.29 on the news before paring gains.

Trump says US to aid stranded ships in Hormuz

Trump said on Sunday the U.S. would begin an effort from Monday to guide ships stranded in the Strait of Hormuz, aimed at aiding neutral countries in the U.S.-Israel war on Iran. 

He provided few actual details on the plan, but said his representatives were “having very positive discussions” with Iran. 

Separately, U.S. Central Command said support would include destroyers, over 100 land and sea aircraft, and 15,000 service members. It was not immediately clear whether the plan would involve direct military action. 

Traffic through the Strait of Hormuz remained disrupted after Iran effectively blocked the waterway in late-February. The channel supplies about 20% of the world’s oil production. 

Iran has vowed to keep Hormuz closed until the U.S. lifts its naval blockade against the country. Washington has insisted that Iran first open the channel and agree to a nuclear deal, leaving both countries at an impasse. 

Ukraine attacks Russian port, tankers 

Concerns over oil supply disruptions extended beyond the Middle East, after Ukraine launched a wave of drone attacks on targets across Russia on Sunday.

Ukraine struck the Baltic Sea port of Primorsk, while also attacking a number of vessels and energy infrastructure in the area. 

Ukraine has repeatedly targeted Russian oil infrastructure as a means of cutting off Moscow’s revenue stream and limiting its war efforts. 

Elsewhere, the OPEC+ said on Sunday they will increase oil production by 188,000 barrels per day in June. This comes after the United Arab Emirates left the producer group on May 1.