DUBAI (Dispatches) -- Dubai and Abu Dhabi stock markets suffered their biggest single-day decline in years on Monday after several commercial ships were allegedly attacked off the coast of the United Arab Emirates.
Saudi shares had their worst day since mid-October after Riyadh said two of its oil tankers were among the vessels hit in the attacks.
Saudi Arabia's index declined 3.6%, with Al Rajhi Bank dropping 4.6% and petrochemical group Saudi Basic Industries falling 5.1%. The index is down nearly 10% since the start of May.
Saudi Arabia said the two Saudi oil tankers were attacked off the coast of the UAE and said it was an attempt to undermine the security of crude supplies.
The UAE said on Sunday that four commercial vessels were sabotaged near Fujairah emirate, one of the world's largest bunkering hubs lying just outside the Strait of Hormuz, but did not say who was behind the attack or describe the nature of it.
"The declines today in the Persian Gulf markets reflect cautious sentiment amongst investors amid regional uncertainty," said Mihir Kapadia, chief executive, Sun Global Investments. "The sabotage attack of two Saudi oil tankers off the coast of the UAE has surprised investors who are already jittery due to rising trade tensions between the U.S. and China."
Shares in National Shipping Company of Saudi Arabia (Bahri) dropped 3%, after trading and shipping sources said the Saudi vessels targeted were Bahri-owned very large crude carrier Amjad and crude tanker Al Marzoqah.
Insurance companies were among biggest fallers on the Saudi market. Persian Gulf Union Cooperative Insurance and Salama Cooperative Insurance each fell 10% after they reported first-quarter losses, citing increased net claims.
The Dubai index was down 4% in the sharpest single-day decline since June, 2016 with 26 of 37 stocks falling and none rising.
Financials also pushed Abu Dhabi's index down 3.3%, its biggest one-day drop since January, 2016.
Qatar's index lost 1.9% with 18 of its 20 stocks declining. Market heavyweight Qatar National Bank decreased 2.8% while lender Masraf Al Rayan was down 3.1%.
Outside the Persian Gulf, Egypt's blue-chip index fell 1.5% mirroring decline in emerging markets as concerns over U.S.-China trade dispute intensified.
Brent crude futures were up 22 cents at $70.84 a barrel. U.S. West Texas Intermediate (WTI) crude futures were up 4 cents at $61.70 a barrel.
Iran: Attacks ‘Alarming’
Iran called attacks on ships in the Persian Gulf "alarming", calling for a probe and warning of "adventurism" by foreign players to disrupt maritime security.
"The incidents in the Sea of Oman are alarming and regrettable," Foreign Ministry spokesman Abbas Mousavi said as he called for clarifications concerning the "exact dimensions" of the attacks on ships.
The spokesman said such incidents would have a "negative impact... on shipping safety and maritime security" in the Persian Gulf.
He also "warned against plots by ill-wishers to disrupt regional security" and "called for the vigilance of regional states in the face of any adventurism by foreign elements."