London (AFP)

Oil prices flew off Monday after the attack on Saudi oil facilities, which sharply reduced the world's supply of black gold, and aroused fears of a military escalation between the United States and Iran.

"This is the biggest single disruption in oil supply in history," said Ipek Ozkardeskaya, an analyst for London Capital Group.

Around 8:45 GMT, oil jumped 8.62% to 65.41 dollars in London, where is quoted the Brent barrel of the North Sea, and 8% to 59.24 dollars in New York for the "light sweet crude ", American reference crude.

At the opening, prices jumped 20% in London, the strongest movement in session since 1991 and the Gulf War.

"The attack has canceled about half of Saudi production, about 5% of world production," said Craig Erlam, Oanda brokerage.

Saturday's explosions sparked fires at the Abqaiq plant, the world's largest oil processing plant, and the Khurais oil field.

The Saudi authorities quickly said there were no casualties. But the vagueness persists over the ability of the world's largest crude exporter to return to normal.

According to experts, Ryad will quickly restore a third of its production. The kingdom has also already pledged to mobilize its vast reserves to cushion the shock, and US President Donald Trump said he is ready to do the same, to cushion the oil shock.

There is "plenty of oil!", He tweeted.

"For the moment, the markets are well supplied with many commercial reserves," confirmed Monday morning the International Energy Agency (IEA).

- Climbing between Washington and Tehran -

If the world is not immediately threatened by a shortage of black gold, markets also manifest Monday by their bloodshed fear of a military escalation between Washington and Tehran.

The United States said it was "ready to respond" to drone attacks after US Secretary of State Mike Pompeo on Saturday accused Iran of being behind the attack.

Yemeni Houthi rebels, backed by Iran and who have been facing a military coalition led by Ryad for the past five years, have claimed responsibility for the attacks on the facilities of the public giant Aramco.

There is no evidence that this "unprecedented attack on global energy supply" has come from Yemen, commented Mike Pompeo on Saturday.

Tehran ruled the accusations "foolish" and "incomprehensible", Foreign Ministry spokesman Abbas Mousavi said in an attempt to justify "future action" against Iran .

China has called on the United States and Iran to "restrain" and avoid any "escalation of tensions in the region". "In the absence of an indisputable investigation that can draw conclusions, it may not be responsible for imagining who should be held responsible" for this incident, said Hua Chunying, a spokesman for Chinese Ministry of Foreign Affairs.

Saudi Crown Prince Mohammed bin Salman, whose country is Iran's great regional rival, assured that Ryad was "willing and able" to respond to this "terrorist aggression".

But James Dorsey, a Middle East expert at Singapore's S. Rajaratnam School of International Studies, has estimated unlikely direct retaliation: "The Saudis do not want an open conflict with Iran (...) They would like others to fight for them, but others are reluctant. "

Before accusing Tehran of causing drone attacks on Saudi oil facilities, Washington had already blamed Iran for attacks and sabotage of oil tankers in the Gulf in May and June.

© 2019 AFP