HOUSTON: Oil futures rose on Thursday as attacks continued on shipping in the Red Sea near Yemen but a large build in US crude inventories curbed gains.

Brent crude futures were up 51 cents to $83.54 a barrel at 11:49 ET (1649 GMT). US West Texas Intermediate crude futures were up 64 cents at $78.55 a barrel.

Two missiles were fired at a vessel off the southeast coast of Yemen on Thursday, causing a fire onboard, British maritime agencies said, as Houthis keep up attacks on shipping to show support for Palestinians in the Gaza war.

“In and around the Red Sea by Iran-backed Houthi rebels on commercial ships are guaranteed to continue keeping the geopolitical risk premium at an elevated level,” PVM Oil’s Tamas Varga said. Even so, a jump in crude inventories last week following refinery maintenance and outages limited gains.

US crude inventories rose by 3.5 million barrels to 442.9 million barrels in the week ending Feb. 16, the US Energy Information Administration said on Thursday, compared with analysts’ expectations in a Reuters poll for a 3.9 million-barrel rise. US crude inventories have climbed amid outages at large refineries that have left utilization rates at the lowest level in two years, though the plants are soon to resume output.

Refinery utilization rates were unchanged last week, at 80.6%, according to EIA data on Thursday, compared with analysts’ expectations of an uptick to 81.5%, according to a Reuters poll. BP’s 435,000 barrel-per-day (bpd) Whiting refinery in Indiana, the largest in the US Midwest, will return to full production in March, according to people familiar with plant operations, after a power outage from Feb. 1.

TotalEnergies’ 238,000-bpd refinery in Port Arthur, Texas, is also working to complete a restart, though it is still operating minimally following a weather-related power outage.