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.

Saudi Arabia cuts ties with Qatar over terror links

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."

10 examples of Saudi Arabia's human rights abuses Show all 10 1 /10 10 examples of Saudi Arabia's human rights abuses 10 examples of Saudi Arabia's human rights abuses In October 2014, three lawyers, Dr Abdulrahman al-Subaihi, Bander al-Nogaithan and Abdulrahman al-Rumaih , were sentenced to up to eight years in prison for using Twitter to criticize the Ministry of Justice. AFP/Getty Images 10 examples of Saudi Arabia's human rights abuses In March 2015, Yemen’s Sunni President Abd-Rabbu Mansour Hadi was forced into exile after a Shia-led insurgency. A Saudi Arabia-led coalition has responded with air strikes in order to reinstate Mr Hadi. It has since been accused of committing war crimes in the country. Getty Images 10 examples of Saudi Arabia's human rights abuses Women who supported the Women2Drive campaign, launched in 2011 to challenge the ban on women driving vehicles, faced harassment and intimidation by the authorities. The government warned that women drivers would face arrest. Getty Images 10 examples of Saudi Arabia's human rights abuses Members of the Kingdom’s Shia minority, most of whom live in the oil-rich Eastern Province, continue to face discrimination that limits their access to government services and employment. Activists have received death sentences or long prison terms for their alleged participation in protests in 2011 and 2012. Getty Images 10 examples of Saudi Arabia's human rights abuses All public gatherings are prohibited under an order issued by the Interior Ministry in 2011. Those defy the ban face arrest, prosecution and imprisonment on charges such as “inciting people against the authorities”. Getty Images 10 examples of Saudi Arabia's human rights abuses In March 2014, the Interior Ministry stated that authorities had deported over 370,000 foreign migrants and that 18,000 others were in detention. Thousands of workers were returned to Somalia and other states where they were at risk of human rights abuses, with large numbers also returned to Yemen, in order to open more jobs to Saudi Arabians. Many migrants reported that prior to their deportation they had been packed into overcrowded makeshift detention facilities where they received little food and water and were abused by guards. Getty Images 10 examples of Saudi Arabia's human rights abuses The Saudi Arabian authorities continue to deny access to independent human rights organisations like Amnesty International, and they have been known to take punitive action, including through the courts, against activists and family members of victims who contact Amnesty. Getty Images 10 examples of Saudi Arabia's human rights abuses Raif Badawi was sentenced to 1000 lashes and 10 years in prison for using his liberal blog to criticise Saudi Arabia’s clerics. He has already received 50 lashes, which have reportedly left him in poor health. Carsten Koall/Getty Images 10 examples of Saudi Arabia's human rights abuses Dawood al-Marhoon was arrested aged 17 for participating in an anti-government protest. After refusing to spy on his fellow protestors, he was tortured and forced to sign a blank document that would later contain his ‘confession’. At Dawood’s trial, the prosecution requested death by crucifixion while refusing him a lawyer. Getty Images 10 examples of Saudi Arabia's human rights abuses Ali Mohammed al-Nimr was arrested in 2012 aged either 16 or 17 for participating in protests during the Arab spring. His sentence includes beheading and crucifixion. The international community has spoken out against the punishment and has called on Saudi Arabia to stop. He is the nephew of a prominent government dissident. Getty

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.

What happened when US officials were asked why they criticised Iran but not Saudi Arabia

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.