The Organization of the Petroleum Exporting Countries once again cut its forecast for global oil-demand growth for this year, as escalating attacks on Gulf shipping continue to disrupt key export routes and send oil prices past $100 a barrel.

The group of oil-rich countries expects global demand to grow by 380,000 barrels a day, down from 580,000 barrels a day previously. Next year's demand growth is now seen at 2.36 million barrels a day, up from a previous estimate of 2.16 million barrels a day.

The closely watched monthly report came after Brent, the global oil benchmark, surpassed $100 a barrel this week for the first time since July as escalating U.S.-Iran clashes and renewed Houthi strikes on Saudi Arabia deepened fears of prolonged supply disruptions. The prospect of a drawn-out war is also fueling concerns over energy-driven inflation, with higher fuel costs threatening to feed through to households, businesses and the broader economy.

In early U.S. trading on Thursday, Brent climbed 4.4% to $105.68 a barrel, while West Texas Intermediate futures gained 4.8% to $100.65 a barrel. Both benchmarks have risen more than 20% this month.

Crude production among OPEC members rose by just 346,000 barrels a day to 24.08 million barrels a day in August, driven by a sharp increase in Iraqi output. Production from OPEC's de facto leader, Saudi Arabia, was constrained by threats to its key export routes, while a U.S. naval blockade strangled Iranian shipments from the Persian Gulf.

Riyadh's output tumbled by roughly 1.9 million barrels a day to 6.24 million barrels a day, while Iranian production fell by 399,000 barrels a day to 2.1 million barrels a day, according to OPEC's latest data.

Before the war, the Strait of Hormuz--a critical artery for global energy markets--used to carry roughly a fifth of the world's oil and liquefied natural gas supplies to international buyers. It remains difficult to gauge how much crude is still moving through the waterway, as some tankers are crossing with their transponders switched off. But with vessels continuing to face the threat of attacks, energy flows through the strait remain highly uncertain.

Earlier this month, key members of the OPEC+ alliance agreed to keep output stable in October after six straight monthly increases as the broader group reviews members' production capacity baselines for future quotas. The war, however, could test the group's cohesion if producers seek to increase output beyond their targets, according to analysts.