Rajeh Badi, press advisor to Yemeni Prime Minister Mohammed Salem Basindwa, said the plan involved dozens of al Qaeda militants dressed in Yemeni army uniforms storming the facilities on the night of the 27th of Muslim month of Ramadan, which was on Sunday.
"The plot aimed to seize the al-Dabbah oil export terminal in Hadramout (province) and the Belhaf gas export facility, as well as the city of Mukalla," Badi told Reuters, referring to the Hadramout provincial capital.
He said the plot was prevented by deploying extra troops around the targeted facilities and banning anyone from entering.
The United States has evacuated some U.S. diplomatic staff out of
Other Western countries, including Britain, France, the Netherlands and Norway, also closed their embassies in Sanaa and some evacuated their staff.
It was not immediately clear if the foiled plot was linked to these security measures.
Yemen, one of the poorest Arab countries, is the base for Al Qaeda in the Arabian Peninsula (AQAP), one of the most active branches of the network founded by Osama bin Laden, and militants have launched attacks from there against the West.
(Reporting Mohammed Ghobari, writing by Sami Aboudi; Editing by Raissa Kasolowsky)