Oil surged above $70 a barrel in early Asian trading after Saudi Arabia said an energy facility was attacked, with prices extending gains after OPEC+ last week said it would keep production steady.

Futures in London jumped as much as 2.6% after rising 4.9% last week. The kingdom said a storage tank in the Ras Tanura export terminal in the country’s Gulf coast was attacked on Sunday by a drone from the sea. Output appeared to be unaffected after the barrage of missiles and drones were intercepted.

Oil climbed last week after Saudi Arabia and OPEC+ made a surprise pledge to maintain output steady in April, accelerating a rally this year that has seen prices surge more than 35%. The move prompted a raft of investment banks to raise their price forecasts, with Goldman Sachs Group Inc. estimating global benchmark Brent will top $80 a barrel in the third quarter.

The attacks are the most serious against the Saudi oil installations since a key processing facility and two oil fields came under fire in September 2019, cutting oil production for several days and exposing the vulnerability of the Saudi petroleum industry. That assault was claimed by the Houthi rebels, although Riyadh pointed the finger at Iran.