Saudi Arabia has shut down all Qatar Airways offices in its kingdom and revoked the airline's licences, according to the state news agency, as the diplomatic row between the tiny kingdom and its Gulf neighbours widens.
Saudi Arabia, Bahrain, the UAE and Egypt cut off diplomatic ties with Doha in a coordinated move on Monday, followed by the internationally recognised governments of Yemen and Libya as well as The Maldives.
Delays and cancellations at airports across the region as the travel ban came into force on Tuesday were the first concrete effects of the escalating crisis.
More than 30 flights leaving Doha were cancelled and pictures and videos which emerged of the city's Hamad International Airport showed it to be eerily quiet.
A total of 27 flights from Dubai to Doha were also cancelled, according to various operators' websites. Qatar Airways, for its part, also suspended all flights to its three Gulf neighbours and Egypt "until further notice".
As well as air travel, land and sea borders have also been severed, leading to food and other supply shortage fears. Foreign diplomats have been recalled and Qatari citizens abroad have been given 14 days to leave the affected countries.
The spat could have a huge economic and political impact on the Middle East - including the region’s many conflicts.
The unprecedented row has been caused in part by backlash over Qatar’s decision to rescue 24 members of the royal family, as well as two Saudi nationals, who were kidnapped by Shia paramilitaries while on a hunting trip in southern Iraq - a deal exclusively revealed by The Independent in April.
Doha’s agreement to pay the extraordinary $500m (£389m) ransom greatly angered its Gulf neighbours, who have long accused it of funding or otherwise supporting controversial groups and meddling in regional affairs, particularly through state-owned broadcaster al-Jazeera.
A statement from Riyadh formally cutting ties on Monday accused Doha of harbouring "terrorist and sectarian groups that aim to destabilise the region including the Muslim Brotherhood, Isis and Al-Qaeda."
The Saudis also accused Doha of supporting Iran-backed "terrorist activities" in the country's east, as well as Shia-majority Bahrain. Any suggestion that Qatar is aiding and abetting Shia Iran - the majority Sunni Gulf's arch-rival - is particularly sensitive.
In a statement from the Qatari Foreign Ministry Doha called the accusations "baseless" and what amounts to a siege of its borders "a violation of [Qatar's] sovereignty.
Iran, which US President Donald Trump singled out as a key source of funding and support for extremist groups during a two-day trip to Riyadh last month, is the secondary target of Monday’s decision by Saudi Arabia and its allies.
On Monday Iran accused Mr Trump of laying the groundwork for the falling out by disturbing the balance of power in the Gulf with his overt backing of Saudi Arabia.
The Qatari authorities have reached out to Kuwait as a mediator, it was reported Tuesday - the first tentative steps towards reconciliation in the spat, the worst to affect relations in the Gulf in decades.
Ruler Sheikh Sabah IV is reportedly preparing to fly to Riyadh for talks with Saudi King Salman.
Qatar's emir, Sheikh Tamim bin Hamad Al Thani, is expected to publicly address the crisis in a s speech later on Tuesday.
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