Brent and West Texas Intermediate crudes rose more than 1% Monday, as investors worried about possible supply disruptions in the Middle East after Iran’s seizure of a British tanker last week, Kallanish Energy reports.

Brent crude oil futures climbed 66 cents a barrel, or 1.02%, to $63.11 a barrel. West Texas Intermediate crude futures settled up 1.1%, or 59 cents, to $56.22/Bbl.

Capping gains, force majeure was lifted on loadings of crude at Libya’s Sharara Oilfield, the country’s largest, whose closure since Friday had caused an output loss of roughly 290,000 barrels per day.

Last week, WTI fell over 7% and Brent lost more than 6%, weighed down by economic worries and the return of U.S. production in the Gulf of Mexico after Hurricane/Tropical Storm Barry passed through.

Iran’s Revolutionary Guards said Friday they had captured a British-flagged oil tanker in the Gulf in response to Britain’s seizure of an Iranian tanker earlier this month.

The move fanned fears of potential supply disruptions in the Strait of Hormuz at the mouth of the Persian Gulf, through which flows roughly 20% of the world’s oil supplies, but no major escalation with Britain or the U.S. appears imminent.

Last week, data showed shipments of crude from Saudi Arabia, the world’s top oil exporter, fell to an 18-month low in May.

Speculative money is returning to oil in response to the escalating dispute between Iran, the U.S. and other Western nations, along with signs of falling supply. In early May, new, tighter U.S. sanctions on Iran took effect.

Goldman Sachs on Sunday lowered its forecast of growth in oil demand for 2019, to 1.28 million Bpd (Mmbpd), citing disappointing global economic activity.

This post appeared first on Kallanish Energy News.