Two oil tankers carrying Saudi crude to China and India reversed course in the Red Sea after Yemen's Iran-aligned Houthi movement threatened to attack vessels involved in transporting Saudi oil.

The move followed the Houthis' announcement of a naval blockade against Saudi Arabia, widening the ongoing conflict involving the United States, Iran, Israel, and regional armed groups.

The development has raised fresh concerns over the security of two of the world's most important energy shipping routes: the Bab el-Mandeb Strait and the Strait of Hormuz.

With access through the Strait of Hormuz already heavily disrupted by the conflict, the Red Sea had become Saudi Arabia's primary alternative export route.The latest threats now place both routes at risk, increasing fears of supply disruptions.Oil prices responded by rising more than 2%, with Brent crude trading above US$91 per barrel.

Meanwhile, the US military continued airstrikes across Iran for an 11th consecutive night, targeting military facilities, missile sites, air defence systems, and maritime capabilities.

Iranian authorities reported explosions in several cities, while health officials said dozens of civilians had been killed and hundreds wounded in the recent strikes.

Iran also launched attacks against US military facilities in Bahrain, Kuwait, and Jordan, while maritime authorities reported damage to tankers in the Strait of Hormuz.US President Donald Trump warned that Washington would respond if the Houthis completely blocked the Bab el-Mandeb Strait.

The conflict has also placed additional financial pressure on the United States, with Defence Secretary Pete Hegseth telling lawmakers that military operations have already cost tens of billions of dollars.Diplomatic efforts continue, with mediators seeking a temporary ceasefire, although fighting across the region remains intense.