Saudi Arabia has shut down its crucial East-West pipeline after it was attacked on Thursday, threatening a vital alternative route for crude exports from the Gulf and putting more upward pressure on oil prices. The official Saudi Press Agency quoted an energy ministry source as saying it had halted operations along the pipeline as a "precautionary measure" after attacks in the Riyadh and Madinah regions caused a "number of injuries".

The Saudi foreign ministry said the pipeline had been hit by drones from Iraq and added that the kingdom would not retaliate "at this stage" after a request from the Iraqi prime minister. The attack on the pipeline came as Iran-backed Houthi rebels this week fired waves of missiles and drones into Saudi Arabia, targeting energy facilities in the kingdom's south.

The 1,200km pipeline, which carries crude from Saudi Arabia's main oilfields in the east to the port of Yanbu on the Red Sea, has allowed the kingdom to continue to export millions of barrels of crude a day despite Iranian restrictions on tankers passing through the Strait of Hormuz. Benchmark Brent crude settled at $104.56 a barrel on Friday, having risen more than 8 per cent over the week.