Around 0030 GMT, the price of West Texas Intermediate was down 5.46 percent at $91.33 a barrel.

However, North Sea Brent crude was up 1.6 percent at $97.68 a barrel.

Oil prices plunged below $100 on Monday as investors raised expectations of a reopening of the Strait of Hormuz, following signs that Washington and Tehran were edging closer to a deal.

But as top Iranian negotiators arrived in Doha for talks to end the war, US Central Command said American forces had attacked missile sites in southern Iran and boats trying to lay mines, threatening a fragile ceasefire that took effect on April 8.