Most Gulf equities fell on Sunday and Boursa Kuwait suspended trading after U.S. and Israeli strikes on Iran prompted retaliatory attacks across nearby U.S. targets in Gulf cities, fanning fears of prolonged regional instability, Reuters reports.

Trading in Middle East markets is an early indicator of how investors measure any impact on assets from oil to safe-haven currencies and gold.

In Saudi Arabia, the Tadawul All Share Index (.TASI) dropped 4.6% at the open, marking its biggest intraday fall since April. Among the biggest decliners were Al Rajhi Bank (-3.3%), Saudi National Bank (-4.5%) and flynas (-4.5%), while oil giant Saudi Aramco gained 2.3%.

The Boursa Kuwait suspended trading as a precautionary measure.

“Gulf markets are under high pressure and volatility as geopolitical tensions trigger risk-averse sentiment, pushing prices lower and resetting expectations,” said Hani Abuagla, senior analyst at XTB MENA. He added that further escalation or damage to the real economy could intensify the sell-off.

Oman’s MSX30 index trimmed losses to 1.5% after dropping more than 3%, with key asset OQ Base Industries down 2.2%. Bahrain’s (.BAX) index fell 0.6%, while Qatar Stock Exchange was closed due to a banking holiday.

Disruptions to shipping through the Strait of Hormuz remain a key risk, weighing on investor sentiment and normal business operations across several sectors, Abuagla noted.

Barclays on Saturday raised its forecast for Brent crude oil prices from $80 to around $100 per barrel.