Trump orders new Iran sanctions after attack on Saudi oil installations

US President Donald Trump announced on Wednesday that he was seeking to impose further sanctions on Iran over a weekend attack on Saudi oil installations.

Washington has tried to build its case that Iran was behind the weekend attack on key Saudi Arabian oil facilities that raised new war worries and sent energy prices spiralling worldwide.

Trump tweeted on Wednesday: "I have just instructed the Secretary of the Treasury to substantially increase Sanctions on the country of Iran!"

He did not elaborate, and Treasury officials could not immediately be reached.

Iran has denied responsibility and warned the US it will retaliate if Tehran is targeted over the attack.

Yemen's Iranian-backed Houthi rebels have claimed the attack in response to the Saudi-led war in Yemen, which has sparked the world's worst humanitarian crisis and killed tens of thousands of people.

The weekend strikes on Abqaiq - the world's largest oil processing facility - and the Khurais oil field in eastern Saudi Arabia roiled energy markets and revived fears of a conflict in the tinderbox Gulf region.