The United States launched fresh strikes on Iran Friday after Tehran-backed Houthi rebels attacked oil tankers in the Red Sea, marking an escalation that pushed crude prices past $100 a barrel.
The US military insisted that the Strait of Hormuz -- through which one fifth of the world's oil passed before the war -- was "open for transit" after Iran pressed on with attacks on tankers using the route in a bid to strongarm them into paying for safe passage.
But the Houthis opened a new front in the war this week when they attacked vessels in the Red Sea, intensifying fears over world crude supplies.
The international oil benchmark Brent crude surged past $100 a barrel on Thursday for the first time since May, up eight percent, as world leaders expressed alarm over the rebels' attacks.
It was hovering just above $100 on Friday morning.
