Oil prices briefly set another record in trading on Monday, Oct. 15, before dropping slightly.

Light, sweet crude hit a record high of $85.20 a barrel in trading on the New York Mercantile Exchange, before falling back down closer to $84 a barrel.

According to The Associated Press, most analysts were blaming the increase on fears that oil supplies would be insufficient for the coming winter months.

The U.S. Energy Information Administration reported last week that supplies were down, and the International Energy Agency stated that oil inventories in the world’s largest industrialized countries were below the five-year average.

Fears that Turkey could take action against Kurdish rebels in northern Iraq also spurred concerns on the oil market, adding more tension to an already tense situation in the Middle East.