Local reports said powerful blasts were heard across wide areas of Yanbu, with smoke rising from the site of the incident.
Saudi authorities have not yet released an official statement on the explosions, and the cause of the incident, along with possible casualties and damage, remains unclear.
Yanbu, located on the Red Sea coast, is one of Saudi Arabia’s key oil export hubs and has been used as a strategic alternative route after disruptions caused by the US war in the Persian Gulf weakened regional energy flows.
Meanwhile, Saudi oil buyers and traders warned that Riyadh could exhaust available export stocks within days if the east-west pipeline is not restored, potentially removing up to 4% of global oil supply from the market.
The pipeline, which was forced offline after drone attacks on Friday, had allowed Saudi Arabia to redirect around 4 million barrels of oil per day to Yanbu, bypassing disruptions in the Strait of Hormuz.
The shutdown has left Yanbu with enough stored crude to sustain exports for only five to seven days, according to industry sources.
Separately, repair estimates for the damaged pipeline remain uncertain, with some sources saying restoration could take five to six weeks, while others believe partial operations could resume sooner.
The disruption comes as global energy markets face severe supply shortages that have pushed fuel prices higher and increased economic pressure worldwide.
The International Energy Agency said Saudi oil supply had already fallen to its lowest level in more than three decades due to reduced flows through the Strait of Hormuz and the Red Sea.
Saudi Arabia reported to OPEC that production dropped to 6.2 million barrels per day in August, down from 10.9 million barrels per day before the start of the war.