March 19 (Reuters) - 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 ( XOM ).

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.