Prices on world oil markets jumped in response to the attacks on Saudi Arabia’s oil refineries.  It was the biggest one-day surge since the 1991 Gulf War. 

Yesterday, Donald Trump tweeted that the U.S. was “locked and loaded” to respond to the attacks, which Secretary Of State Mike Pompeo blamed on Tehran. The Iranians responded on Monday saying the country was ready for “full-fledged war” with the U.S.

Iranian-backed rebels in Yemen have claimed responsibility for the attacks. But the Washington Post reports:

A Saudi military spokesman said Monday that a preliminary investigation found that the weapons used against the facilities were Iranian, according to Reuters news agency.  The spokesman, Col. Turki al-Malki, also said the attack did not originate in Yemen and that investigations were underway to determine the launch location, Reuters reported.

Iran has denied any involvement. China and European countries have warned against hastily assigning blame. 

Despite earlier reports that damage to the Saudi facility could be repaired quickly, Reuters reports, “Two sources briefed on the operations of state oil company Saudi Aramco told Reuters it might take months for Saudi oil production to return to normal. Earlier estimates had suggested it could take weeks.”

ABC News is reporting the refineries were attacked with much more sophisticated weaponry than previously reported:

Iran launched nearly a dozen cruise missiles and over 20 drones from its territory in the attack on a key Saudi oil facility Saturday, a senior Trump administration official told ABC News Sunday.

It is an extraordinary charge to make, that Iran used missiles and drones to attack its neighbor and rival Saudi Arabia, as the region teeters on the edge of high tensions.