Update: moments ago Reuters, citing the Saudi State News Agency, confirmed the report:

POWER RELAY FACILITY SET ON FIRE BY PROJECTILE FIRED FROM YEMEN TOWARDS SOUTHERN SAUDI ARABIAN CITY OF NAJRAN- SAUDI STATE NEWS AGENCY

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While oil is spiking thanks to the dollar's kneejerk reaction lower following Yellen's (not really) hawkish speech, another reason for the move higher appears to be an unconfirmed report by Iran's PressTV that Yemeni forces have fired ballistic missiles at the facilities belonging to the Saudi state oil giant Aramco in the kingdom’s southwest.

From the report:

Yemeni forces have fired ballistic missiles at the facilities belonging to the Saudi state oil giant Aramco in the kingdom’s southwest. The retaliatory attack took place on Friday, hitting targets in Saudi Arabia’s Jizan region and causing considerable damage to the Aramco facilities there, Yemen’s al-Masirah television reported. The Saudi military has been pounding Yemen since March last year to undermine Yemen’s Houthi Ansarullah movement and to restore power to the former president, Abd Rabbuh Mansur Hadi, a staunch ally of Riyadh. Nearly 10,000 people, most of them civilians, have been killed in Riyadh’s military aggression which lacks any international mandate.

An alleged video of the explosion (unconfirmed).

Historically, the accuracy of PressTV reports has been spotty at best, so waiting for confirmation may be prudent, although as of this moment algos are buying first and not even bothering to ask questions.