The Qatari television network Al Jazeera reported on Sunday that the attacks had caused significant damage to Saudi energy giant Aramco's Pump Station 8.
The drone strikes reportedly caused a 4-meter rupture in one of the station's main oil pipes, causing severe leakage in an area of around a thousand square meters.
The Yemeni army, in coordination with the Houthi Ansarullah movement, announced last Tuesday that they had launched drones to attack "critical facilities" deep inside Saudi territory.
Hours later, Saudi officials confirmed that two oil pumping stations in Dawadmi and Afif provinces in the Riyadh region had been targeted and that oil flow in the east-west oil pipeline, which carries between 3 and 5 million barrels a day, had been brought to a halt.
The attacks have been regarded as the beginning of a new era in the years-long deadly war, which has so far killed thousands of Yemeni civilians and plunged the impoverished country into a growing humanitarian crisis.
War enters new stage
Afif and Dawadmi are located about 850 kilometers from Sa'ada, Yemen's northernmost city.
The attack bears extra significance at this stage of the war because it indicates that Yemeni forces were able to fly their armed drones a long distance and carry out precision strikes and then fly them back while evading Saudi defenses all along.
The long-range drones open unlimited possibilities for Yemeni resistance forces, which have already surpassed all expectations by surviving the massive Saudi onslaught and mounted a potent response with an arsenal of ballistic missiles.
A source within the Yemeni Ministry of Defense said on Sunday night that the oil facilities attacked on May 14 were only two of the 300 critical targets that the resistance forces were planning to attack in the near future in retaliation for the Saudi aggression.
The targets include military bases and other vital infrastructure across Saudi Arabia and the United Arab Emirates -- the two main perpetrators of the war, the unnamed official said, adding the positions of Saudi mercenaries inside Yemen were also on the list.
The source asserted that the war had entered a "new chapter" and "substantial developments" were expected in all areas.