Prices for North Sea Brent crude oil on Monday took their biggest one-day jump ever as markets reacted to a devastating drone attack on Saudi oil production.

The attacks, which knocked an estimated five percent of global capacity offline, have stoked fears that costlier energy could be a drag on the global economy — a prospect that sent global stocks into the red.

In London, Brent benchmark crude for November delivery rocketed 14.6 percent higher, adding $8.80 to settle at $69.02 per barrel — the largest increase since trading in the contract began in 1988, according to Bloomberg.

Meanwhile in New York, West Texas Intermediate likewise jumped 14 percent to $62.90, the biggest increase in more than a decade.

The weekend drone attack on Saudi petroleum facilities knocked about five percent of global capacity offline, rattling markets.

US and Saudi officials have blamed Iran for the attacks but Tehran has dismissed the accusations, suggesting that Washington was seeking a pretext to attack the Islamic republic.

Meanwhile, Saudi authorities are considering whether to delay an IPO for oil giant Aramco after this weekend’s attack on its oil facilities shut down a major chunk of global production, people with knowledge of the matter said.

Huthi rebels backed by Iran, who have been locked in battle with a Saudi-backed military coalition for years, claimed responsibility for the strikes on Aramco facilities.

US President Donald Trump on Monday promised to supply oil to US allies following the attacks.