The crude oil markets—including some physical markets—are showing signs of tightening as concerns about crude oil transit times due to bypassing the volatile Red Sea continue to drag on, traders, analysts, and LSEG data now show.

Historically, turmoil in the Middle East have caused crude oil prices to spike—sometimes in a big way, even if only temporarily. This time around, oil prices have become more resilient and haven’t moved much over the past month, despite the significant conflict in the Red Sea that has caused many crude oil tankers to take the long way around rather than traverse the Red Sea.

But that doesn’t mean that markets aren’t tightening, particularly in Europe and Africa. Rising Chinese demand for crude oil and outages in Libya and North Dakota have joined forces to increase competition for the crude oil that doesn’t have to go through the Suez Canal, Reuters said on Friday, before adding that the Brent crude futures market was at its most bullish point of the last two months today. And when it comes to the Red Sea issue, it is the Brent contract that is most affected, Kpler analyst Viktor Katona told Reuters on Friday.

Premiums for the first-month Brent contract to the six-month contract rose to $2.15 per barrel today—the highest spread since November and a clear indication that the market is viewing the market for crude as tightly supplied for prompt deliveries.

The market for North Sea crude is also highly backwardated, with Johan Sverdrup crude trading at a $2.80 premium to dated Brent. Trading sources told Reuters that the Sverdrup demand jump could be tied to the perception that Middle Eastern crude shipments could be delayed to Europe.