Qatar's Foreign Affairs Ministry said there was "no legitimate justification" for the countries' decision, though it vowed its citizens wouldn't be affected by it.
The crisis was likely to have wide-ranging consequences, not just for Qatar and its citizens but around the Middle East and for Western interests.
World Cup 2022 host Qatar denies the allegations and called the decision from its neighbouring countries to cut ties "unjustified" and with "no basis in fact", according to the BBC.
Gulf Arab states and Egypt have already long resented Qatar's support for Islamists, especially the Muslim Brotherhood which they regard as a risky political enemy.More news: Maldives follows Saudi Arabia, Egypt in severing ties with Qatar
Bahrain jumped first with an announcement that Qatari diplomats should vacate the country within 48 hours, and vice versa, while citing Qatar's "support for armed terrorist activities and funding linked to Iranian groups to carry out sabotage and spreading chaos in Bahrain".
According to reports, Qatar had provided United States dollars 8 billion financial support to Morsi and was the main Gulf backer of Brotherhood's government.
The Sunni Muslim nation said it "has always pursued a policy of promoting peace and stability in the Middle East".
The list of Hamas officials Qatar has asked to leave its territory - reportedly gleaned from interrogations of Palestinian security prisoners in Israel - included Saleh al-Arouri, said to be the group's military commander in the West Bank and the founder of the West Bank branch of Hamas's military wing, the Izz ad-Din al-Qassam Brigades.More news: Pens strike back, 1-1 in Game 2 vs Pens
At the time of writing there had been no official statements from Egyptair, Saudi or Gulf Air confirming whether their flights to and from Doha will also be suspended - Business Traveller will update this page as we receive more news.
Meanwhile, flag carrier Saudi Airlines said it was suspending flights to Qatar with immediate effect. It was unclear whether the suspension would be extended.
The former army chief and now president, Abdel Fattah al-Sisi, along with the new government's allies in Saudi Arabia and the UAE, blacklist the Brotherhood as a terrorist organisation.
He also encouraged Qatar and its neighbours to "sit down together and address these differences".More news: Dan Aykroyd slams director over 'Ghostbusters' remake costs
Few days ago, Qatar ruler Sheikh Tamim bin Hamad Al-Thani had questioned the growing anti-Iran sentiment in the region and described Tehran as "a big power" in the region.
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