Oil prices have jumped after a fire shut down the main pipeline delivering Canadian crude oil to refineries in the US Midwest.
Most Canadian oil exports to the US use Enbridge's pipelines
The blaze near Enbridge's Clearbrook oil terminal in Minnesota killed two employees, with local officials saying it could burn for three days.
Pipelines from Canada carry about 1.9 million barrels of oil per day and the closure has hit 20% of US oil imports.
A barrel of New York light crude oil rose $3.77, or 4.2%, to $94.39.
In London, Brent crude gained $2.23, or 2.5%, to $92.04.
The incident has reversed some of the recent price falls caused by the smaller than expected drop in US oil stockpiles.
"My initial impression is that (this) will put a halt to the slide in oil prices and put us back on the march towards $100 a barrel," said Mark Pervan, senior commodities analyst at ANZ.
"The timing is pretty bad. We are coming to the strongest demand period for crude with the approach of the northern winter."
Canada is the biggest supplier of foreign crude oil to the US and nearly all of it is delivered along Enbridge's pipelines.