Stock markets in the Gulf fell sharply on Monday as a fast-spreading new coronavirus strain that has shut down much of the United Kingdom fuelled concerns that a resurgence of infections could stunt the pace of reopening economies.

The variant, which officials say is up to 70% more transmissible than the original, also prompted concerns about a wider spread. 

Brent crude slid $1.54, or 3.0%, to $50.72 a barrel by 0510 GMT after rising 1.5% and touching its highest since March last Friday. 

Saudi Arabia's benchmark index traded 1.8% lower, with Al Rajhi Bank dropping 1.5%, while Dr Sulaiman Al-Habib Medical Services slid 3.2%.

The kingdom suspended late on Sunday all international commercial flights for a renewable week except for the foreign flights already in Saudi Arabia which will be allowed to leave, state news agency SPA reported quoting an interior ministry source. 

Dubai's main share index tumbled 4.3%, its biggest intraday fall since March, as most of the stocks on the index were in red including sharia-compliant lender Dubai Islamic Bank, which retreated 4.9%.

Elsewhere, DXB Entertainment declined 5%, to become the top loser on the index.

Dubai property company Meraas, which owns more than half of DXB Entertainments, intends to make a conditional offer to acquire the remaining shares in the loss-making theme park group and take it private, stock exchange filings showed on Sunday.

The Abu Dhabi index fell 1.7%, dragged down by a 1.1% fall in the country's largest lender First Abu Dhabi Bank and a 4.8% decline in Abu Dhabi Commercial Bank.

In Qatar, the index eased 0.4%, hit by a 1.4% drop in utility firm Qatar Electricity and Water.

Meanwhile, the Gulf state's Ministry of Public Health approved on Sunday the Pfizer and BioNTech COVID-19 vaccine for emergency use, Reuters reported, citing Qatar state news agency QNA's tweet. 

(Reporting by Ateeq Shariff in Bengaluru) ((AteeqUr.Shariff@thomsonreuters.com; +918061822788;))