Saudi shares slumped at the start of trading Sunday, the first session after drone attacks on two major oil facilities knocked out more than half the OPEC kingpin's production.
The Tadawul All-Shares Index, which tracks the Arab world's largest capital market, sank three percent, shedding some 200 points in the first few minutes before regaining some of the losses.
Just under one hour into the session, TASI was down 1.50 percent at 7,715 points.
The key energy sector plunged 4.7 percent, while the telecom and banking sectors each slid three percent.
The market was also affected by an announcement from the Saudi Basic Industries Co. (SABIC), one of the world's largest petrochemicals producers, that the industry faced a shortage of raw materials.
It did not name the reason but said the issue arose on Saturday -- the day of the drone attack.
Other bourses in the Gulf also dropped. Dubai Financial Market was down 1.1 percent, Abu Dhabi and Qatar markets declined 0.4 percent each, while Kuwait shares sank 0.8 percent and Bahrain's bourse slid 0.9 percent.
Oman's shares were flat.
Explosives-laden drones struck the processing plants at Abqaiq and Khurais in the Eastern Province early on Saturday morning, knocking out some 5.7 million barrels per day of crude oil production and around two billion cubic feet of natural gas output.
The Abqaiq plant handles some seven million bpd of crude oil and billions of cubic feet of natural gas.
State-owned energy giant Aramco in March acquired 70 percent of SABIC, the largest capitalised firm on the Saudi market, for $69.1 billion.