Investing.com -- A supertanker has been observed at Saudi Arabia's main oil export terminal in the Persian Gulf, marking the first such sighting in nearly a month as the kingdom works to sustain shipments amid threats to its exports in the Red Sea.

A satellite image from the European Union's Sentinel 2 orbiter, captured Tuesday, shows a very large crude carrier moored at one of Ju'aymah's single-point moorings, part of the Ras Tanura oil export complex. The vessel can load approximately 2 million barrels of crude. The previous sighting of a ship at this location was in mid-July, though satellite images are not available daily.

Saudi Arabia had increased its Persian Gulf exports when a brief interim peace deal between the US and Iran permitted tankers to transit the Strait of Hormuz earlier this year. Few ships have been observed at the kingdom's ports inside the Gulf since then.

The top OPEC producer has redirected millions of barrels daily to its Red Sea port of Yanbu. Tracking these flows has become more difficult after Yemen's Houthi militants announced they would begin attacking Saudi-linked ships.

Riyadh reported to the Organization of the Petroleum Exporting Countries that its oil output rose by just over a million barrels a day in July but remains substantially below pre-war levels.

Tuesday's images also show another tanker moored at the Ras Tanura sea island, about 20 miles south of Ju'aymah. The vessel's dimensions indicate it is a Suezmax class ship, capable of carrying about 1 million barrels of cargo. This is the second ship observed there this month, following a smaller Aframax-sized vessel seen a week ago.