Oil giant Saudi Aramco’s SAMREF refinery in the Red Sea port of Yanbu was targeted in an aerial attack on Thursday, an industry source said, adding there was minimal impact. Iran’s Islamic Revolutionary Guard Corps on Thursday issued an evacuation warning to several oil facilities across Saudi Arabia, the UAE and Qatar, including SAMREF, which is a joint venture between Saudi Aramco and Exxon Mobil . Yanbu is currently the only export outlet for any crude oil out of Gulf Arab countries as Iran has effectively shut the Strait of Hormuz, the narrow waterway it shares with Oman, through which a fifth of the world’s oil supply normally flows. Saudi Aramco did not immediately respond to an emailed request for comment.