Crude oil prices continued to move higher on Tuesday as a fresh escalation in the Middle East raised concerns about possible disruptions to regional energy supplies.

Market sentiment was further unsettled after President Donald Trump reportedly warned of possible military action against Kharg Island, Iran’s main oil export hub. Any disruption to operations at the island could have a significant impact on global oil flows and further tighten supply conditions.

Adding to the pressure on energy markets, drone and missile attacks on Russian refineries have reduced refining capacity, creating another potential strain on the global fuel supply chain.

With risks emerging on both the crude production and refining sides, investors are closely watching developments in the Middle East and Russia for signs of further supply disruptions. WTI crude oil futures were last quoted at $86.66 per barrel, up more than 1% on the day, while Brent crude moved above the $91-per-barrel mark.