Egypt, Saudi Arabia, the United Arab Emirates and Bahrain severed diplomatic ties with Qatar on Monday over what they say is Doha's support of terrorist groups, widening the rift between some of the most powerful Arab countries.
The four Arab countries accuse Doha of backing organisations including the Muslim Brotherhood, Daesh and Al-Qaeda, as well as Iran-backed militants.
The Arab countries say the Gulf nation adopts policies that aim to "destabilise the region" and are "threatening Arab national security," in violation of international obligations and agreements under the Gulf Cooperation Council.
Shortly after the announcement, Libya's eastern-based government and Yemen's internationally recognised government followed regional allies in cutting diplomatic ties with Doha.
Arab nationals in Qatar and Qataris abroad
Saudi Arabia, the UAE and Bahrain have given Qatari tourists and residents two weeks to leave their territories, saying they will ban Qatari nationals from entering or passing through their states.
Riyadh said "Saudi citizens are not allowed to travel to, reside in, or pass through Qatar," giving its nationals 14 days to depart.
Bahrain and the UAE have given Qatari diplomatic missions 48 hours to leave.
Egypt has given the Qatari Ambassador 48 hours to leave the country, though it has made no statement regarding its nationals in Qatar or Qatari nationals in Egypt.
Qatar, meanwhile, says its government will take all necessary steps to ensure that the new measures by the Arab states will not affect the "normal life" of citizens and residents.
However, the Qatari embassy in Abu Dhabi has asked citizens to leave the United Arab Emirates within 14 days to comply with Abu Dhabi's decision to sever ties with Doha.
Travel to and from Qatar
Egypt, the UAE, Saudi Arabia and Bahrain said they are closing their airspace and sea ports to Qatar over "national security concerns."
Both the UAE and Bahrain said the closure of transportation ties will take effect within 24 hours.
Abu Dhabi's state-owned Etihad Airways, the UAE's flagship airline, and the Dubai-based airline Emirates said they would suspend all flights to and from Doha starting Tuesday morning until further notice.
The Saudi civil aviation authority said it is banning all Qatari airlines and flights from entering its airspace as off Tuesday, and has banned all Qatari planes from landing at the kingdom's airports.
The authority also said that the kingdom's commercial and private airlines are not allowed to serve Qatar.
However, the Saudi government said it will not disallow Qatari pilgrims from visiting Mecca.
Qatar's troops in the Saudi-led coalition fighting in Yemen
The Saudi-led Arab coalition fighting rebels for more than two years in Yemen said it is expelling Qatar from the coalition over the country's support of terrorist groups including Daesh and Al-Qaeda.
Qatar says there is "no legitimate justification" for the cutting of diplomatic ties by the four Arab nations, and that the decision is a "violation of its sovereignty."
This is not the first row between Qatar and other Arab Gulf countries in recent years, though tensions have now reached their highest levels in years.
In 2014, during an eight-month dispute, Saudi Arabia, Bahrain and the UAE withdrew their ambassadors from Doha over accusations that Qatar supports militant groups.
However, Qatari nationals were not expelled and travel ties remained unaffected.
Some Egyptian banks say they have halted dealings with the Qatari currency, though Egypt's central bank governor Tarek Amer was quoted in local media as saying that the bank has not issued any decisions in this regard.
Qatar's main stock index fell more than 7 percent after the severing of diplomatic ties.
Qatar is the world's biggest producer of liquefied natural gas.
Brent crude oil, the international benchmark, rose more than 1 percent at one point before paring gains on Monday after the diplomatic rift. It stood at $50.29 a barrel earlier on Monday.
The severing of transportation ties with Doha by Egypt, Saudi Arabia, the UAE and Bahrain is also expected to cause the Gulf Arab state major economic losses.