Two oil tankers carrying Saudi crude to China and India reversed course in the Red Sea on Tuesday after Yemen's Houthi rebels declared a naval blockade against Saudi Arabia and warned they would target ships sailing to or from Saudi ports, raising fresh concerns over global energy supplies and maritime trade.

According to Reuters, citing LSEG shipping data, the tankers made U-turns and headed north toward the Suez route. One vessel, the very large crude carrier (VLCC) Xin Long Yang, departed the Saudi Red Sea port of Yanbu on Monday carrying about 2 million barrels of crude oil bound for China. Bloomberg reported that the tanker halted before reaching the Yemeni border and reversed course instead of continuing through the Bab el-Mandeb Strait.

The detour would increase the voyage from around 7,000 miles to more than 17,000 miles, substantially raising freight costs and delivery times. Because a fully loaded VLCC cannot transit the Suez Canal at full draft, the vessel would first need to unload roughly half of its cargo into Egypt's Sumed pipeline, then reload at the Mediterranean terminal before continuing to China.

The Houthi announcement comes amid a sharp escalation following the collapse of an interim peace agreement between the United States and Iran. By threatening shipping in the Red Sea in addition to the Strait of Hormuz, the Houthis have widened the risks facing two of the world’s most strategically important maritime trade routes, heightening concerns over oil supplies, shipping costs and broader disruptions to global commerce.